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Joined: 31/12/2012
Location: New ZealandPosts: 9263
| Posted: 10:02am 17 Sep 2022 |
Hi all.
Cos I needed a board to drive a 2.8" SPI LCD with the PM, I came up with this board that piggy-backs onto a standard 2.8" SPI module with touch:
The board is four-layer. Four-layer boards used to be very expensive compared to double-sided, but these days, that is not the case. These four-layer designs cost a whole two bucks more then the standard double-sided price. Seven bucks for five vs five bucks if it were double-sided, so it makes sense to simply go directly to four-layer if it is easier to route everything, and it is on this size.
All PM pins are routed out to a box-header. 2x3 header for 3v3 and ground connections for experimenters. RTC module with EEPROM memory chip, HC12 wireless module, linear LDO regulator, piezo sounder and reset button all on-board.
With the aid of a daughterboard, you could easily add anything else you wanted to to the PCB stack such as the LPF for audio out or a PWM motor driver or something like that.
Needs 9v DC supply if you want to use the piezo, as they don't tend to "Start" on 5v or less, but if you KNOW you won't be using the piezo or the GUI touch click sound, then you can run the board from 5v.
EDIT: Forgot to add the OPTION TOUCH command to the silkscreen, but I will be doing that shortly.
Edited 2022-09-17 20:09 by Grogster
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