@Wuerfel_21 Thanks for the corrections. Do you know what, besides serial TX and RX are already used on the Raspberry Pi? I'm thinking maybe the thing to do is to make a fully compatible GPIO connections. It seems that the signals on the Raspi are 3v3 inputs and outputs anyways. Do you know why the pinouts of the Raspi GPIO is numbered all over the place? Was it because the BGA was just easier to route this way? I never really interfaced to it, but I would imagine that it is quite a PITA working around that odd ordering.
@Wuerfel_21 Thanks for the corrections. Do you know what, besides serial TX and RX are already used on the Raspberry Pi? I'm thinking maybe the thing to do is to make a fully compatible GPIO connections. It seems that the signals on the Raspi are 3v3 inputs and outputs anyways. Do you know why the pinouts of the Raspi GPIO is numbered all over the place? Was it because the BGA was just easier to route this way? I never really interfaced to it, but I would imagine that it is quite a PITA working around that odd ordering.
Do you know why the pinouts of the Raspi GPIO is numbered all over the place? Was it because the BGA was just easier to route this way? I never really interfaced to it, but I would imagine that it is quite a PITA working around that odd ordering.
Yes, they are like that because it's easier to route that way. Arduinos are the same, BTW, the library just abstracts the actual pin numbers away (well, AVR pins aren't really numbered sequentially to begin with).
@Wuerfel_21 Thanks for the corrections. Do you know what, besides serial TX and RX are already used on the Raspberry Pi? I'm thinking maybe the thing to do is to make a fully compatible GPIO connections.
Well, the Pi GPIO has all sorts of stuff hardwired to certain pins. There's hardware SPI, there's 18bit parallel video, there's I2S, lots of things.
Now I am leaning towards a Raspberry Pi footprint. With pin usage of:
Power In/Serial Console/Programing through USB-C 2pins shared with GPIO header
HDMI 8pins
Audio In/Out/Composite Video 3pins
BlueToothLE module 2pins (sticks out of the Raspberry Pi 3 case where the ethernet usually is)
4xUSB 8pins
HyperRAM 11pins (177MB/s required for 24bit 1080p @30fps)
microSD 4pins (full MMC speed one can be added to GPIO header)
28 pins on GPIO header (including console/programming serial)
Legacy adapter board for those that prefer VGA & PS2, a board that plugs into the HDMI connector, has VGA out (3+0to2 pins), keyboard 1pin and second pin jumperable if using doing SoG or Composite Sync on the VGA, mouse 2pins)
Now for a comparison of pinouts:
Raspberry Pi pinouts ripped off from https://www.raspberrypi.org/documentation/usage/gpio/
As well as simple input and output devices, the GPIO pins can be used with a variety of alternative functions, some are available on all pins, others on specific pins.
PWM (pulse-width modulation)
Software PWM available on all pins
Hardware PWM available on GPIO12, GPIO13, GPIO18, GPIO19
SPI
SPI0: MOSI (GPIO10); MISO (GPIO9); SCLK (GPIO11); CE0 (GPIO8), CE1 (GPIO7)
SPI1: MOSI (GPIO20); MISO (GPIO19); SCLK (GPIO21); CE0 (GPIO18); CE1 (GPIO17); CE2 (GPIO16)
I2C
Data: (GPIO2); Clock (GPIO3)
EEPROM Data: (GPIO0); EEPROM Clock (GPIO1)
Serial
TX (GPIO14); RX (GPIO15)
P2 Pi pinouts:
As well as simple input and output devices, the GPIO pins can be used with a variety of alternative functions.
PWM(pulse-width modulation)
Hardware Assisted (through SmartPin configuration) on all pins.
SPI
SPI0: MOSI (any pin); MISO (any pin); SCLK (any pin; CEO (any pin), CE1 (any pin or not used)
SPI1: MOSI (any pin); MISO (any pin); SCLK (any pin; CEO (any pin), CE1 (any pin or not used)
...
SPI6: MOSI (any pin); MISO (any pin); SCLK (any pin; CEO (any pin), CE1 (any pin or not used)
I2C
I2C0: Data (any pin); Clock (any pin)
I2C1: EEPROM Data (any pin); EEPROM Clock (any pin)
...
I2C12: Data (any pin); Clock (any pin)
Serial
Console TX (Pin63); RX (Pin62) Correct me if I got these backwards.
Serial1: TX (any pin); RX (any pin)
Serial2: TX (any pin); RX (any pin)
...
Serial13: TX (any pin); RX (any pin)
Analog Input (any # of pins)
Analog Output (any # of pins)
... need to add pin feature discriptions here as more driver objects become available.
Streamer (any pin)
Now, if you were a true maker, or an EE student, or a hobiest that likes to know what's going on under the hood, which Pi would you rather have on your bench? @"Ken Gracey" You see the advantage you have here when you compare them like that? There are a lot of Pi hats that could work already, plus you guys could make some others like a 3click hat. I am guessing if you were able to build them for $100 in the USA, and maybe even get those fancy Purple&Gold PCB's' like (which is the PE6502 board that uses a Propeller), you could sell lots of them. I would really your opinion/feedback @"Ken Gracey" and others.
EE student, or a hobiest that likes to know what's going on under the hood, which Pi would you rather have on your bench?
3B+ , powered by Ultibo, which is Object Pascal based bare metal environment.
All of them will do, except RPi 4/400 which is still poor documented while Zero/1/2/3 was already reverse engineered and/or good documented. There are a lot of bare metal tutorials and 2 ready-made environments: Circle (C++ based) and Ultibo.
These are open source environments, a lot of things inside RPi can be learned from them.
Of course.. I have many RPis on my desk (0,0W,1b,2,3,3a+,3b+,4,400)
Raspberry Pi pinouts(...)
RPi has GPIO0..GPIO26 connected to the GPIO pins (mixed up... ) All of them can be simple in or out, up to 5 functions are defined for every pin.
There are registers for selecting the function (one reg for 10 pins, 3 bit for function#)
There are 2 registers to read pins
There are 2x2 registers to set and reset pins (different for set and reset), so you have to do 2 writes to set any 1-0 combination on 32 pins
There are 2 hardware PWMs/serializers (up to 250 MHz on input) - and also there is i2s
You can connect 18 GPIO pins directly to GPU making a "VGA666" (6 bits per color)
There are several UARTS and i2c
For a P2Pi the simplest thing to do is to connect P0..P26 as in RPi.
This will make a lot of RPi hats work with a P2 Pi
P28-P31 - 2x USB for kbd/mouse. Can a hub be connected to P2 USB?
P32 to P43 for HyperRAM/Flash
P44,P45 - audio out jack - maybe P27 as mic in (instead of composite, which can be accessed via a dumbadapter on HDMI socket)
P46,P47 - audio in (in place of one USB socket)
P48..P55 - HDMI socket, make an hdmi->VGA and composite dumb adapters as accessories sold with the board
P57..61 - SD,
as eth is not possible (or maybe it is?) use RJ connector to connect the serial port on P62,P63
@pik33 to each his own. I personally don't have an interest in learning Pascal. What do you think the user base for bare metal Pi's? Also, the Pi won't do much for analog without external devices.
For your choice of pins, I think SD only needs 4 pins, plus there needs to be another pin on the audio jack for either Composite video or mic can share the same connector. The dumbadapter pins should be saved for PS/2 Keyboard & Mouse, unless SyncOnGreen, which will free up another pin.
HyperRam only used 11 pins, so on your count it would be 32 through 42.
Audio in might be good, but I think people would prefer USB over Audio in, but I could be wrong.
I think you did well to pick lower pin numbers for Pi compatibility and also byte boundaries to start of HyperRAM and HDMI as these 2 are high bandwidth.
Even though LEDs on 56 and 57 are somewhat standard, I think it would be a waste to use whole pins for them.
The FTDI/CP2102/Peter's Micro for USB2serial can drive LEDs for downloading.
Now I am leaning towards a Raspberry Pi footprint. With pin usage of:
Power In/Serial Console/Programing through USB-C 2pins shared with GPIO header
HDMI 8pins
Audio In/Out/Composite Video 3pins
BlueToothLE module 2pins (sticks out of the Raspberry Pi 3 case where the ethernet usually is)
4xUSB 8pins
HyperRAM 11pins (177MB/s required for 24bit 1080p @30fps)
microSD 4pins (full MMC speed one can be added to GPIO header)
28 pins on GPIO header (including console/programming serial)
I'm not following - I would expect a Raspberry Pi footprint board, to have a 40 pin header ?
In order to bring out all 32 io pin per side, 4 pins are always GND and 4 GND pins have jumper options for P2 port pins.
P2 used this way, can replace a Pi-master (eg for talking to Displays), or it can plug into a Pi as a slave.
Yeah, a 40pin Pi compatible header was the idea, but there are only 28 GPIO's on a Pi. The rest are power and ground. So, yeah, access to a whole host of PiHats would be really nice.
Having a single board was also the idea, like other Pies to keep costs down. Board sandwich would drive up costs.
Also having all the amenities that people need to develop as well as maker tools and control down to the bear metal is also the idea.
What's with that special ID EEPROM? I wasn't thinking there needed to be serial ROM there, just Pin0 and Pin1, unless there is a real good reason for it.
I was thinking Made in the USA, even if it is more expensive. Maybe @"Ken Gracey" and @cgracey will decide to make it if enough people are interested. They've got everything already drawn, parts sourced in the form of the "P2-ES Eval Board Accessory Set", and have fixed some noise issues(IIRC) that arose with the 1st P2Eval, so to avoid them should be easier..
What do you think the user base for bare metal Pi's?
I am employed to do a commercial project using bare metal Pis making money out of this
You can use OpenGL ES and have a camera attached using Ultibo - and it only needs RPi firmware and a custom kernel7.img which is 2 MB. No system, you can switch the pi off without closing, no SD needed after start, if you don't want to write data on it, you can even hot-swap the SD.
These ID pins are simply GPIO 0 and 1
Also, the Pi won't do much for analog without external devices.
P2 can be such an external device. A "realtime-and-analog hat"
There is a closed source RPi firmware blob, which is needed to initialize RPi and there is no escape for that, as it runs on VideoCore.
A cycle accurate stuff can be done, you can free a core from interrupts and system tasks, then it is your core so do what you want with it.
There is a problem with realtime i/o stuff as the pins are connected via system bus which timings are unpredictable. (delay between set a bit in register and get this bit on your pin) The jitter can be several hundred nanoseconds. It is much lower in one-core Pis. The Propeller is much more predictable and consistent in real time stuff.
You can use built-in PWMs (2 of them) for signal generation (I made an audio driver for Ultibo as there was no such driver ready - https://github.com/pik33/SimpleAudio )
After Ultibo start, you got the CPU in hypervisor mode and MMU set 1:1 to physical RAM addresses. All of this can be changed later.
You have an access to VC4 via its standard mailbox interface, so all things work, including OpenGL ES and camera.
It is free pascal based but you can link your C code easy; ready made C code can be linked too if it can be compiled to .a file. I made an MP3 player adding ready-made libmad library to it.
As a real world application example ... I am currently working on a project that uses a RasPi for video surveillance and motion detection written in Python with four separate USB video feeds running essentially a video Server on the Pi so that it can be accessed anywhere in the world that you have internet. The PCB that the RasPi is connected to is basically a glorified custom PLC. The PCB firmware, written in pure PIC Assembly language, is capable of monitoring and reading all the listed items below to communicate in simple serial packets to any device capable of constructing a proper packet. In this case a Raspberry PI but it could just as easily be a BASIC STAMP.
-24 Inputs (each fuse protected at 500mA with visual fuse blown indicator)
-24 Outputs (each fuse protected at 5A with visual fuse blown indicator)
-Integrated QUAD USB Port with software controllable Enable/Disable per port
-Integrated USB2Audio
-Integrated 20Watt Class D Audio Amplifier
-External GPS monitoring
-RH and Temperature sensor (DHT22)
-Dual Raspberry PI connector with dedicated 5V power supply
-Integrated SLA battery monitoring and charging
-Voltage Boost circuit for SLA charging overhead requirement
-Automatic switching between Battery and Main power in the event of a power failure
-External Load Cell sensing for monitoring kiosk weight
-12V input from SLA Battery and Main power (10 Amp fused)
-Integrated 5V regulator for main board
-Integrated 3.3V regulator for external GPS board
-Programmable INPUT alarms: LOW to HIGH, HIGH to LOW, ANY change
-Main Power failure alarm
5A outputs, GPS, battery backup, opencv. Hook those 5A outputs onto wheel motors and this kiosk can surely detach from mains and stalk it target until they buy something...
The load cell is interesting, I never thought of that for a kiosk, but it makes perfect sense to verify successful operation
I don't want to derail this thread because I think it has merit... To gain any momentum with this you are going to need to think from an industrial/consumer demand perspective.
@Tubular - Yeah that was a fun board to design and write firmware for.
Think Automated Propane Kiosk, ICE machines, and other Vending Machines.
If you could substitute the Raspberry Pi functionality for a Propeller and consider the clientele for such a service you would have a considerable market to contend with.
Comments
Yes, they are like that because it's easier to route that way. Arduinos are the same, BTW, the library just abstracts the actual pin numbers away (well, AVR pins aren't really numbered sequentially to begin with).
Well, the Pi GPIO has all sorts of stuff hardwired to certain pins. There's hardware SPI, there's 18bit parallel video, there's I2S, lots of things.
Power In/Serial Console/Programing through USB-C 2pins shared with GPIO header
HDMI 8pins
Audio In/Out/Composite Video 3pins
BlueToothLE module 2pins (sticks out of the Raspberry Pi 3 case where the ethernet usually is)
4xUSB 8pins
HyperRAM 11pins (177MB/s required for 24bit 1080p @30fps)
microSD 4pins (full MMC speed one can be added to GPIO header)
28 pins on GPIO header (including console/programming serial)
Legacy adapter board for those that prefer VGA & PS2, a board that plugs into the HDMI connector, has VGA out (3+0to2 pins), keyboard 1pin and second pin jumperable if using doing SoG or Composite Sync on the VGA, mouse 2pins)
Now for a comparison of pinouts:
Raspberry Pi pinouts ripped off from https://www.raspberrypi.org/documentation/usage/gpio/
As well as simple input and output devices, the GPIO pins can be used with a variety of alternative functions, some are available on all pins, others on specific pins.
PWM (pulse-width modulation)
Software PWM available on all pins
Hardware PWM available on GPIO12, GPIO13, GPIO18, GPIO19
SPI
SPI0: MOSI (GPIO10); MISO (GPIO9); SCLK (GPIO11); CE0 (GPIO8), CE1 (GPIO7)
SPI1: MOSI (GPIO20); MISO (GPIO19); SCLK (GPIO21); CE0 (GPIO18); CE1 (GPIO17); CE2 (GPIO16)
I2C
Data: (GPIO2); Clock (GPIO3)
EEPROM Data: (GPIO0); EEPROM Clock (GPIO1)
Serial
TX (GPIO14); RX (GPIO15)
P2 Pi pinouts:
As well as simple input and output devices, the GPIO pins can be used with a variety of alternative functions.
PWM(pulse-width modulation)
Hardware Assisted (through SmartPin configuration) on all pins.
SPI
SPI0: MOSI (any pin); MISO (any pin); SCLK (any pin; CEO (any pin), CE1 (any pin or not used)
SPI1: MOSI (any pin); MISO (any pin); SCLK (any pin; CEO (any pin), CE1 (any pin or not used)
...
SPI6: MOSI (any pin); MISO (any pin); SCLK (any pin; CEO (any pin), CE1 (any pin or not used)
I2C
I2C0: Data (any pin); Clock (any pin)
I2C1: EEPROM Data (any pin); EEPROM Clock (any pin)
...
I2C12: Data (any pin); Clock (any pin)
Serial
Console TX (Pin63); RX (Pin62) Correct me if I got these backwards.
Serial1: TX (any pin); RX (any pin)
Serial2: TX (any pin); RX (any pin)
...
Serial13: TX (any pin); RX (any pin)
Analog Input (any # of pins)
Analog Output (any # of pins)
... need to add pin feature discriptions here as more driver objects become available.
Streamer (any pin)
Now, if you were a true maker, or an EE student, or a hobiest that likes to know what's going on under the hood, which Pi would you rather have on your bench? @"Ken Gracey" You see the advantage you have here when you compare them like that? There are a lot of Pi hats that could work already, plus you guys could make some others like a 3click hat. I am guessing if you were able to build them for $100 in the USA, and maybe even get those fancy Purple&Gold PCB's' like
3B+ , powered by Ultibo, which is Object Pascal based bare metal environment.
All of them will do, except RPi 4/400 which is still poor documented while Zero/1/2/3 was already reverse engineered and/or good documented. There are a lot of bare metal tutorials and 2 ready-made environments: Circle (C++ based) and Ultibo.
These are open source environments, a lot of things inside RPi can be learned from them.
Of course.. I have many RPis on my desk
RPi has GPIO0..GPIO26 connected to the GPIO pins (mixed up... ) All of them can be simple in or out, up to 5 functions are defined for every pin.
There are registers for selecting the function (one reg for 10 pins, 3 bit for function#)
There are 2 registers to read pins
There are 2x2 registers to set and reset pins (different for set and reset), so you have to do 2 writes to set any 1-0 combination on 32 pins
There are 2 hardware PWMs/serializers (up to 250 MHz on input) - and also there is i2s
You can connect 18 GPIO pins directly to GPU making a "VGA666" (6 bits per color)
There are several UARTS and i2c
For a P2Pi the simplest thing to do is to connect P0..P26 as in RPi.
This will make a lot of RPi hats work with a P2 Pi
P28-P31 - 2x USB for kbd/mouse. Can a hub be connected to P2 USB?
P32 to P43 for HyperRAM/Flash
P44,P45 - audio out jack - maybe P27 as mic in (instead of composite, which can be accessed via a dumbadapter on HDMI socket)
P46,P47 - audio in (in place of one USB socket)
P48..P55 - HDMI socket, make an hdmi->VGA and composite dumb adapters as accessories sold with the board
P57..61 - SD,
as eth is not possible (or maybe it is?) use RJ connector to connect the serial port on P62,P63
For your choice of pins, I think SD only needs 4 pins, plus there needs to be another pin on the audio jack for either Composite video or mic can share the same connector. The dumbadapter pins should be saved for PS/2 Keyboard & Mouse, unless SyncOnGreen, which will free up another pin.
HyperRam only used 11 pins, so on your count it would be 32 through 42.
Audio in might be good, but I think people would prefer USB over Audio in, but I could be wrong.
I think you did well to pick lower pin numbers for Pi compatibility and also byte boundaries to start of HyperRAM and HDMI as these 2 are high bandwidth.
Even though LEDs on 56 and 57 are somewhat standard, I think it would be a waste to use whole pins for them.
The FTDI/CP2102/Peter's Micro for USB2serial can drive LEDs for downloading.
This new 1GHz RISC-V 'Pi variant', includes such a 40 pin header.
https://beagleboard.org/beaglev
The P2D2Pi variant layout I did, uses this 40 pin pin mapping (repeat for each 32 port block ). This is 2 layer routable.
~~~~~~~~~~~~~~~~ P2D2Pi FLiP and Pi4 Pin mappings ~~~~~~~~~~~~~~~~~ https://www.element14.com/community/docs/DOC-92640/l/raspberry-pi-4-model-b-default-gpio-pinout-with-poe-header Some GND pins have SB jumpers (NO) for P2 signals, allowing all 32 IO per 40 pin header. PI4 P2D2Pi FLiP CN1 (Other 40 pin, CN3 Pm = P(n-32 )) P2 Pi4 Std Pi .___. Std Pi Pi4 P2 VBP +3V3---1-|O O|--2--+5V 5V P32 (SDA1) GPIO2---3-|O O|--4--+5V 5V P33 (SCL1) GPIO3---5-|O O|--6--_ GND P35 TXD3 (GPIO_GLCK) GPIO4---7-|O O|--8-----GPIO14 (TXD0) P34 P37j PiGND _--9-|O.O|-10-----GPIO15 (RXD0) P36 P39 (GPIO_GEN0) GPIO17--11-|O O|-12-----GPIO18 (GPIO_GEN1) P38 P41 (GPIO_GEN2) GPIO27--13-|O O|-14--_ PiGND P40j P43 (GPIO_GEN3) GPIO22--15-|O O|-16-----GPIO23 (GPIO_GEN4) P42 VBP +3V3--17-|O O|-18-----GPIO24 (GPIO_GEN5) PWM0 P44 P46 (SPI0_MOSI) GPIO10--19-|O.O|-20--_ PiGND P45j P48 (SPI0_MOSO) GPIO9 --21-|O O|-22-----GPIO25 (GPIO_GEN6) P47 P50 (SPI0_SCLK) GPIO11--23-|O O|-24-----GPIO8 (SPI0_CE0_N) P49 GND _-25-|O O|-26-----GPIO7 (SPI0_CE1_N) RTS3 P51 P53 SDA0 (EEPROM) ID_SD---27-|O O|-28-----ID_SC ID EEPROM SCL0 P52 P55 RXD3 GPIO5---29-|O.O|-30--_ P54j P57 CTS3 GPIO6---31-|O O|-32-----GPIO12 PWM0 P56 F.IO1 P58 PWM1 GPIO13--33-|O O|-34--_ GND F.CLK P60 GPIO19--35-|O O|-36-----GPIO16 P59 F.IO0 U.TXD P62 GPIO26--37-|O O|-38-----GPIO20 P61 F.CSN GND _-39-|O O|-40-----GPIO21 P63 U.RXD '---' 40W 0.1" PIN HDRIn order to bring out all 32 io pin per side, 4 pins are always GND and 4 GND pins have jumper options for P2 port pins.P2 used this way, can replace a Pi-master (eg for talking to Displays), or it can plug into a Pi as a slave.
Having a single board was also the idea, like other Pies to keep costs down. Board sandwich would drive up costs.
Also having all the amenities that people need to develop as well as maker tools and control down to the bear metal is also the idea.
What's with that special ID EEPROM? I wasn't thinking there needed to be serial ROM there, just Pin0 and Pin1, unless there is a real good reason for it.
I was thinking Made in the USA, even if it is more expensive. Maybe @"Ken Gracey" and @cgracey will decide to make it if enough people are interested. They've got everything already drawn, parts sourced in the form of the "P2-ES Eval Board Accessory Set", and have fixed some noise issues(IIRC) that arose with the 1st P2Eval, so to avoid them should be easier..
You can use OpenGL ES and have a camera attached using Ultibo - and it only needs RPi firmware and a custom kernel7.img which is 2 MB. No system, you can switch the pi off without closing, no SD needed after start, if you don't want to write data on it, you can even hot-swap the SD.
These ID pins are simply GPIO 0 and 1
P2 can be such an external device. A "realtime-and-analog hat"
A cycle accurate stuff can be done, you can free a core from interrupts and system tasks, then it is your core so do what you want with it.
There is a problem with realtime i/o stuff as the pins are connected via system bus which timings are unpredictable. (delay between set a bit in register and get this bit on your pin) The jitter can be several hundred nanoseconds. It is much lower in one-core Pis. The Propeller is much more predictable and consistent in real time stuff.
You can use built-in PWMs (2 of them) for signal generation (I made an audio driver for Ultibo as there was no such driver ready - https://github.com/pik33/SimpleAudio )
After Ultibo start, you got the CPU in hypervisor mode and MMU set 1:1 to physical RAM addresses. All of this can be changed later.
You have an access to VC4 via its standard mailbox interface, so all things work, including OpenGL ES and camera.
It is free pascal based but you can link your C code easy; ready made C code can be linked too if it can be compiled to .a file. I made an MP3 player adding ready-made libmad library to it.
Here is a video channel: https://www.youtube.com/c/UltiboLive/videos
Here is a link to a similar type of video processing I am doing:
https://www.pyimagesearch.com/2020/06/01/opencv-social-distancing-detector/
I didn't sucker into buying this guys software, so I figured out how to do it on my own through a few nights of intense Google digging.
As a real world application example ... I am currently working on a project that uses a RasPi for video surveillance and motion detection written in Python with four separate USB video feeds running essentially a video Server on the Pi so that it can be accessed anywhere in the world that you have internet. The PCB that the RasPi is connected to is basically a glorified custom PLC. The PCB firmware, written in pure PIC Assembly language, is capable of monitoring and reading all the listed items below to communicate in simple serial packets to any device capable of constructing a proper packet. In this case a Raspberry PI but it could just as easily be a BASIC STAMP.
-24 Inputs (each fuse protected at 500mA with visual fuse blown indicator)
-24 Outputs (each fuse protected at 5A with visual fuse blown indicator)
-Integrated QUAD USB Port with software controllable Enable/Disable per port
-Integrated USB2Audio
-Integrated 20Watt Class D Audio Amplifier
-External GPS monitoring
-RH and Temperature sensor (DHT22)
-Dual Raspberry PI connector with dedicated 5V power supply
-Integrated SLA battery monitoring and charging
-Voltage Boost circuit for SLA charging overhead requirement
-Automatic switching between Battery and Main power in the event of a power failure
-External Load Cell sensing for monitoring kiosk weight
-12V input from SLA Battery and Main power (10 Amp fused)
-Integrated 5V regulator for main board
-Integrated 3.3V regulator for external GPS board
-Programmable INPUT alarms: LOW to HIGH, HIGH to LOW, ANY change
-Main Power failure alarm
The load cell is interesting, I never thought of that for a kiosk, but it makes perfect sense to verify successful operation
@Tubular - Yeah that was a fun board to design and write firmware for.
Think Automated Propane Kiosk, ICE machines, and other Vending Machines.
If you could substitute the Raspberry Pi functionality for a Propeller and consider the clientele for such a service you would have a considerable market to contend with.