Just got mine and I have a quick question. Which pins do I use for i2c communications? The Arduino uses analog 4 and 5 but it looks like these are inputs only on the ASC.
Which pins do I use for i2c communications? The Arduino uses analog 4 and 5 but it looks like these are inputs only on the ASC.
Check the schematic. They're P15 (SCL) and P14 (SDA). Played with its MCP yesterday and used both pins to check the analog stuff. Note that it uses 1k series resistors which may be a bit high for certain purposes (can be bridged).
Check the schematic. They're P15 (SCL) and P14 (SDA). Played with its MCP yesterday and used both pins to check the analog stuff. Note that it uses 1k series resistors which may be a bit high for certain purposes (can be bridged).
After looking at the schematic I don't see where these pins are brought out to the outside world. Could someone point out my overlooking? Thanks.
Wow, i haven't been on in a while, but i wanted to say that i did get the ASC working with the SD shield. I had to buy a 4GB uSD card though... I have done a little work on a new program(A program loader for ASC) and i will release it soon. I will start a different thread so i don't clog up this one... Sorry for not being on much. I have been pretty busy starting my own PC repair business, but i have a little down time, so i will be playing around with the prop and ASC a little more. And i will still try to fulfill my promise to get the ASC in a project:) I was thinking,it would be cool to try and port over the Arduinio shield libraries to SPIN to help the ASC newbies adjust a little better? Any ideas?
Weren't you having problems with 4G cards? did you mean you had to buy a 2gig? As for the project, if porting the librtaries sounds interesting to you, go for it. Whatever gets you excited.
@Martin... YES, Sorry. I meant the 2GB SD card. I just broke down and bought a couple(Not a bad price on Newegg). And i will get working on the libraries right away:)
Yes, the RGB adapter provides a standard VGA output. Any of the several VGA drivers from the Object Exchange including the one packaged with the Propeller Tool will work. Here's one. This one expects an I/O pin group number when initialized. The Propeller ASC provides an extra group of I/O pins that the RGB adapter uses and these are I/O pins 16..23 which would be group number 2.
If you're on Windows, you can use any of the VGA demos included with the Propeller Tool.
File > Open From... > Propeller Library - Demos
They all should work without modification. The ASC uses pin group 16 to 23 which is the same as the Parallax Demo board. Try those demos and if you still get no image we'll diagnose further.
Was your VGA adapter pre-assembled or did you solder it? Look at the picture on this page and compare it to what you have. Are the resistors in the right configuration? Have you checked for solder bridges? Have you checked the continuity of all the connections?
There is a schematic for the VGA adapter linked on my Wiki.
If you don't have an oscilloscope, you can use a plain volt meter. Load and run one of the demos mentioned above. While it's running, put the neg probe on the "GND" pad and, with the pos probe, measure each of the labeled holes directly under the "Propeller hat" logo. You should see anywhere from 0.15 volts to 3.3 volts. With the reset button held in, you should see about 0.28 volts on all the pads.
Found the problem, was forgotten to solder the connectors starting at 6,7 (2*8)
So there was no connection to the p16..p23.
Last question. What to do with the holes numbered P16 .. P23
I think I should close these bridges to make a connection between the propeller P16 .. P23 and the resistors R1..R8
You need not do anything with the two columns of holes labeled P16...P20. They are for probing the wave forms with an oscilloscope. Each pair are connected together and to the resistors.
I want to use the I2C connection of the Propeller ASC.
How can I have acces to these in SPIN?
I have seen in the schematic that the connection is CH4(SDA) and CH5(SDL), but
I see no direct connection to the output/input of the propeller
If you look again at the schematic, you'll see that SDA is also connected through a 1K resistor to P14 and SCL is connected through a 1K resistor to P15. You could put pullup resistors like 10K on these and attach an I2C device to the resulting bus. Any of the I2C drivers from the Object Exchange could be used although some of them (like Basic_I2C_Driver) assume that the SCL and SDA I/O pins are in the opposite order and the references (SDA := SCL + 1) have to be changed (to SDA := SCL - 1).
Thanks for the help, but when I look at the schematic (pasc-e.pdf) I see only a text at pin 14 and 15. I cant see that ther is a connection between CH4 and CH5.
But when I understand you right there is a connection between these pins, zo when I wont to use the ASC board and the I2C I use only to adress the right data to P14 and P15!
Propeller: OUTA[INA](14) <--> SDA on Arduino header "ANALOG IN 4".
Propeller: OUTA(15) --> SCL on Arduino header "ANALOG IN 5".
In some cases it is common in schematics to only list connections by name. This is done to reduce the "rats nest" appearance that can quickly form.
There is an error on the schematic, it lists those resistors as 1K when they are actually 2.2K. I will correct that.
Also there are two solder jumpers, just to the right of the crystal when looking at the back of the ASC. You will want to bridge those, upper to lower, with solder blob if you are using a 3.3 volt I2C circuit.
5 volt --> solder bridge open
3.3 volt --> solder bridge closed
I'm finally getting to experiment with it and wanted to try to implement a couple of knobs via the
MPC3008. The OBEX yielded two objects -
....MCP3008.spin
and
.....ADC_INPUT_example_-_Archive__Date_2011.10.17__Time_15.59.zip
by Brandon Nimon
The latter has this suggested input circuit:
''* Example wiring would be as follows: *
''* R1 *
''* ADC─┳──┳──input *
''* C1 R2 *
''*   *
''* R1: 10K (high impedance input is helpful, 10K should be the minimum) *
''* R2: 100K (this effectively creates a voltage divider, but also drives input to *
''* zero volts when not in use) *
''* C1: 0.01µF (10000pF is the about the maximum you would want to use. The *
''* capacitor reduces jitter or spikes but also reduces resolution). *
So: I'm thinking a 10K pot, one end on +5, other end on ground and the wiper tied to the
input of the above.
You can use that input circuit if you want, I suspect it's there to reduce HF noise. But if you only need to poll the knob a few times a second, you can also connect the wiper directly to the 3008 and use the built in averaging method in MCP3008.spin. Try it both ways and see, you won't blow anything up with a 10K pot.
For anyone wanting to fiddle with basic analog and digital I/O with the ASC, I highly recommend Sparkfun's "Danger Shield".
You can use that input circuit if you want, I suspect it's there to reduce HF noise. But if you only need to poll the knob a few times a second, you can also connect the wiper directly to the 3008 and use the built in averaging method in MCP3008.spin. Try it both ways and see, you won't blow anything up with a 10K pot.
For anyone wanting to fiddle with basic analog and digital I/O with the ASC, I highly recommend Sparkfun's "Danger Shield".
This product has been
retired from our catalog
and is no longer for sale.
This page is made available
for those looking for datasheets
and the simply curious.
Please refer to the description
to see if a replacement part is
available.
Comments
Paul
Is the Propeller ASC RGB adapter a real VGA output?
Wich object can I use from the exchange to test this adapter?
Thanks in advance.
Jan Kromhout
Hellevoetsluis-nl
File > Open From... > Propeller Library - Demos
They all should work without modification. The ASC uses pin group 16 to 23 which is the same as the Parallax Demo board. Try those demos and if you still get no image we'll diagnose further.
EDIT:
Thanks, Mike. That is a good example too.
Tried many programs include the one `mike supposed but with no results.
Monitor is oke, check this with the quick proto board.
How can I check?
Thanks.
Jan Kromhout
There is a schematic for the VGA adapter linked on my Wiki.
If you don't have an oscilloscope, you can use a plain volt meter. Load and run one of the demos mentioned above. While it's running, put the neg probe on the "GND" pad and, with the pos probe, measure each of the labeled holes directly under the "Propeller hat" logo. You should see anywhere from 0.15 volts to 3.3 volts. With the reset button held in, you should see about 0.28 volts on all the pads.
Try that and let us know what you find.
So there was no connection to the p16..p23.
Last question. What to do with the holes numbered P16 .. P23
I think I should close these bridges to make a connection between the propeller P16 .. P23 and the resistors R1..R8
Thanks.
Jan Kromhout
You need not do anything with the two columns of holes labeled P16...P20. They are for probing the wave forms with an oscilloscope. Each pair are connected together and to the resistors.
I want to use the I2C connection of the Propeller ASC.
How can I have acces to these in SPIN?
I have seen in the schematic that the connection is CH4(SDA) and CH5(SDL), but
I see no direct connection to the output/input of the propeller
Thanks for any help.
Cheers,
Jan Kromhout
Hellevoetsluis-NL
But when I understand you right there is a connection between these pins, zo when I wont to use the ASC board and the I2C I use only to adress the right data to P14 and P15!
Cheers,
Jan Kromhout
Hellevoetsluis-NL
Propeller: OUTA(15) --> SCL on Arduino header "ANALOG IN 5".
In some cases it is common in schematics to only list connections by name. This is done to reduce the "rats nest" appearance that can quickly form.
There is an error on the schematic, it lists those resistors as 1K when they are actually 2.2K. I will correct that.
Also there are two solder jumpers, just to the right of the crystal when looking at the back of the ASC. You will want to bridge those, upper to lower, with solder blob if you are using a 3.3 volt I2C circuit.
5 volt --> solder bridge open
3.3 volt --> solder bridge closed
I'm finally getting to experiment with it and wanted to try to implement a couple of knobs via the
MPC3008. The OBEX yielded two objects -
....MCP3008.spin
and
.....ADC_INPUT_example_-_Archive__Date_2011.10.17__Time_15.59.zip
by Brandon Nimon
The latter has this suggested input circuit:
So: I'm thinking a 10K pot, one end on +5, other end on ground and the wiper tied to the
input of the above.
Does that sound workable?
For anyone wanting to fiddle with basic analog and digital I/O with the ASC, I highly recommend Sparkfun's "Danger Shield".
OOPS!
Might be a problem with that soon...
How many do you have in stock??
But I finally did connect with Microchip about the 3008.
Data sheet lives here...
http://ww1.microchip.com/downloads/en/DeviceDoc/21295d.pdf
(since I didn't see it on the WIKI)
twas from what google turned up today... https://www.sparkfun.com/products/9597
but the item number...
Dunno CS.
I may be stuck in a time warp.
Causality is so messy.
Knowes someone where to download the documentation for the MCP???? chip (Analog/Digital) that is on the ASC+ board.
http://ww1.microchip.com/downloads/e...Doc/21295d.pdf