Ray, what about the larger 2.5" version like I have. Are they easy to find in the US?
Ray, I've often thought about hacking into cheap displays. I like this one because it's tiny. I'm not really interested in larger ones. Although, I have seen 7" digital photo frames around for $30 now... That's got me thinking...
Got graphics demo working on the CSTN type displays.
Able to talk to the Flash and Real time clock now.
Found a spot for the 3-axis accelerometer.
Got a break and found one unit with smaller, 1.5mm high switches and was able to find them on Mouser.
Now, I have confidence that I can get the switches working...
Running of the LiPo battery pack now. Haven't done stress test yet, but it went >1 hour with backlight on full.
If everything works out, I may have some to sell by XMas
PS: I found a compatible 32MB SPI flash chip on Digikey for <$4
PSS: I put in a couple pads that if you solder together, will allow you to force reset high and therefore use as a PropPlug
Here's a photo of the unit I'm testing out the PropPlug mode with...
I've decided to hardwire a spare Prop pin directly to the Reset line to prevent the DTR signal from causing a reset. There is a potential problem that a code mistake could make it impossible to reset the unit without unsoldering the battery. I've made sure there's a trace we can cut with a knife to dissable this feature though.
This 4-pin header detracts from the visual appearance a bit, but some people might find it useful. You could also plug this into a breadboard and use it as a serial display...
Got the new batch of PCB boards in! Suprisingly, I don't appear to have made an major blunders this time. I'm still checking it out, but so far everything seems to work.
Major advance is that the buttons work now...
I've added these optional features:
1. A Prop pin is connected directly to the Reset line so that the device can be used as a PropPlug replacement.
2. Added an SMT speaker/buzzer so that it can be used as an alarm clock. It may also play music, don't know yet.
3. Place for a 3-axis accelerometer.
4. As an afterthough, I think I found a way to use 1 pin to measure the battery voltage. Still needs to be tested...
I think I can take orders soon, if anybody is interested... I'm still thinking about a name, but am leaning towards PKS (Propeller Keychain System).
I'd like to have the price start at $30, but haven't look close enough at that yet...
I'll probably do as low a base price as I can and then sell optional extras to make a profit...
One dilema I have is that Amazon.com will only sell me 3 of each color...
I can get them elsewhere, but for more and without the free shipping...
I'll probably have to impose an initial 2/person initial limit because supplies are so limited and I'd like to get these into the hands of as many developers as possible...
Let me take an inital stab at my costs:
$10 for the Coby
$9 for the PCB (that will come down if I later order a huge batch of boards)
$8 for the Prop
$5 for the FTDI chip
$3 for the RTC
$3 for the switches
$2 for the eeprom
$1 for the 5MHz crystal
$1 for the header
$1 for various resistors and capacitors.
-> So that's $43 without any profit...
But, I can leave off the FTDI, RTC, EEPROM, header and 5MHz crystal (and run at 24Mhz with the Coby crystal).
Then, it's down to about $30.
jazzed, I'll give you a PCB for free, since you got me into this mess... List of part numbers may take a while, but I can ship a board now... Just email me the address where you want it...
Okay you got us all excited with that $30 estimate. I want at least two even if they are $100 each.
PS I didn't see the accelerometer on the parts cost. I would like to have that too.
Sorry about that, I didn't add up the numbers until now... Still, I think it could be $30 for a bare-bones version eventually. But, it'll be much more fun fully populated.
I did leave off the accelerometer. But, that's only 2 or 3 dollars. I'm not sure I can put those on without a custom solder stencil though... But, I can try.
Rayman,
That's okay if you don't solder it. Just include it and I can have the assembly staff at my work solder it on for me.
They can hand solder 0201 size resistors!!!
Just found some time to work on this project...
Finally got data written and read back from the Flash chip.
I was hoping to use Mike Green's Winbond flash chip driver, but something must be different because it doesn't work for the SST chips of the Coby. Still, his driver is nice so hopefully we'll be able to fix that issue.
Also, tested the battery voltage monitor.
So, I think the hardware all checks out.
I tried to combine the CSTN and TFT drivers into one file, but there's just too many differences between them to make that simple...
Now, I'll start building units to ship out... Maybe by New Year...
Here are high-res scans of the top and bottom of the new circuit board.
Because the battery voltage monitor was an afterthought, it needs the red jumber wire to work...
Ok, first unit is off the assembly line! This one is for jazzed.
I've got one more gift to make and then I'll make them to sell.
(This isn't a very good picture)
This one is with the TM128128 CSTN lcd. It actually has a slightly different init sequence, but the one for the COG CSTN lcd seems to work fine, so I'll leave it alone until I hear of a problem...
jazzed, I can sell the PCB for $12 each (+shipping). They cost me $9 each at this point.
I'll try to create a web page with sample code and schematic in the next couple days...
Ok, jazzed should get the very first production unit tomorrow (or maybe Friday).
So, I figured it's time to post some code...
I just uploaded all my current test codes to here: http://www.rayslogic.com/Propeller/Products/PKS/PKS.htm
There's still a lot of work to do to turn these into an OS...
Bean, Ok, I'm working on one for you now... Does $50 sound OK? That's essentially my cost, at least I think so (haven't crunched the numbers yet).
But, these things take forever to make right now. So, I would like to send just one for now. I think there's other people waiting... When I feel more comfortable with this idea, I'll invest in a stencil that will make it 10x easier...
I just completed the second unit and learned this: This one has a COG-C144 type CSTN LCD. For some reason, it needed a contrast setting of 90 instead of 60 like the other two TM128128 type CSTN displays needed. So, I'm not totally sure if this is a unit to unit variation or type to type variation. Anyway, I've now added a SetContrast() function call to the CSTN driver. BTW. I though my test unit was a COG-C144 display (and maybe it was at one point), but it's actually a TM128128, just like the one I sent jazzed.
Ok, but it may be a few days...
BTW: I just opened up a couple new Coby's and guess what... One has a different kind of Flash chip: 25Q80SCP
It appears to be code compatible, but who knows... I wonder if they could get away with copying the JEDEC ID or not...
Anyway, I'm starting to think that no 2 of these devices are actually the same...
Comments
Ray, I've often thought about hacking into cheap displays. I like this one because it's tiny. I'm not really interested in larger ones. Although, I have seen 7" digital photo frames around for $30 now... That's got me thinking...
Cheated though and rigged up this setup to sniff the init sequence...
Got graphics demo working on the CSTN type displays.
Able to talk to the Flash and Real time clock now.
Found a spot for the 3-axis accelerometer.
Got a break and found one unit with smaller, 1.5mm high switches and was able to find them on Mouser.
Now, I have confidence that I can get the switches working...
Running of the LiPo battery pack now. Haven't done stress test yet, but it went >1 hour with backlight on full.
If everything works out, I may have some to sell by XMas
PS: I found a compatible 32MB SPI flash chip on Digikey for <$4
PSS: I put in a couple pads that if you solder together, will allow you to force reset high and therefore use as a PropPlug
I've decided to hardwire a spare Prop pin directly to the Reset line to prevent the DTR signal from causing a reset. There is a potential problem that a code mistake could make it impossible to reset the unit without unsoldering the battery. I've made sure there's a trace we can cut with a knife to dissable this feature though.
This 4-pin header detracts from the visual appearance a bit, but some people might find it useful. You could also plug this into a breadboard and use it as a serial display...
Got the new batch of PCB boards in! Suprisingly, I don't appear to have made an major blunders this time. I'm still checking it out, but so far everything seems to work.
Major advance is that the buttons work now...
I've added these optional features:
1. A Prop pin is connected directly to the Reset line so that the device can be used as a PropPlug replacement.
2. Added an SMT speaker/buzzer so that it can be used as an alarm clock. It may also play music, don't know yet.
3. Place for a 3-axis accelerometer.
4. As an afterthough, I think I found a way to use 1 pin to measure the battery voltage. Still needs to be tested...
I think I can take orders soon, if anybody is interested... I'm still thinking about a name, but am leaning towards PKS (Propeller Keychain System).
What is the price ?
Bean
I'll probably do as low a base price as I can and then sell optional extras to make a profit...
One dilema I have is that Amazon.com will only sell me 3 of each color...
I can get them elsewhere, but for more and without the free shipping...
$30 sounds okay.
How about 4 for $100+shipping ?
Bean
Bill
Let me take an inital stab at my costs:
$10 for the Coby
$9 for the PCB (that will come down if I later order a huge batch of boards)
$8 for the Prop
$5 for the FTDI chip
$3 for the RTC
$3 for the switches
$2 for the eeprom
$1 for the 5MHz crystal
$1 for the header
$1 for various resistors and capacitors.
-> So that's $43 without any profit...
But, I can leave off the FTDI, RTC, EEPROM, header and 5MHz crystal (and run at 24Mhz with the Coby crystal).
Then, it's down to about $30.
Ooops, forgot to add $4 for the optional speaker.
Bean
Edit: I've read over the thread and I understand now what rayman is doing. Count me in for one full kit.
Thanks!
David
PS I didn't see the accelerometer on the parts cost. I would like to have that too.
Bean
I did leave off the accelerometer. But, that's only 2 or 3 dollars. I'm not sure I can put those on without a custom solder stencil though... But, I can try.
That's okay if you don't solder it. Just include it and I can have the assembly staff at my work solder it on for me.
They can hand solder 0201 size resistors!!!
Bean
Just found some time to work on this project...
Finally got data written and read back from the Flash chip.
I was hoping to use Mike Green's Winbond flash chip driver, but something must be different because it doesn't work for the SST chips of the Coby. Still, his driver is nice so hopefully we'll be able to fix that issue.
Also, tested the battery voltage monitor.
So, I think the hardware all checks out.
I tried to combine the CSTN and TFT drivers into one file, but there's just too many differences between them to make that simple...
Now, I'll start building units to ship out... Maybe by New Year...
Because the battery voltage monitor was an afterthought, it needs the red jumber wire to work...
I've got one more gift to make and then I'll make them to sell.
This one is with the TM128128 CSTN lcd. It actually has a slightly different init sequence, but the one for the COG CSTN lcd seems to work fine, so I'll leave it alone until I hear of a problem...
jazzed, I can sell the PCB for $12 each (+shipping). They cost me $9 each at this point.
I'll try to create a web page with sample code and schematic in the next couple days...
So, I figured it's time to post some code...
I just uploaded all my current test codes to here:
http://www.rayslogic.com/Propeller/Products/PKS/PKS.htm
There's still a lot of work to do to turn these into an OS...
I'd like to purchase two when you get them made. Let me know.
Bean
But, these things take forever to make right now. So, I would like to send just one for now. I think there's other people waiting... When I feel more comfortable with this idea, I'll invest in a stencil that will make it 10x easier...
I just completed the second unit and learned this: This one has a COG-C144 type CSTN LCD. For some reason, it needed a contrast setting of 90 instead of 60 like the other two TM128128 type CSTN displays needed. So, I'm not totally sure if this is a unit to unit variation or type to type variation. Anyway, I've now added a SetContrast() function call to the CSTN driver. BTW. I though my test unit was a COG-C144 display (and maybe it was at one point), but it's actually a TM128128, just like the one I sent jazzed.
Bean
BTW: I just opened up a couple new Coby's and guess what... One has a different kind of Flash chip: 25Q80SCP
It appears to be code compatible, but who knows... I wonder if they could get away with copying the JEDEC ID or not...
Anyway, I'm starting to think that no 2 of these devices are actually the same...