Timeline for How can Rpi use a matrix key pad to read multiple, up to 256 keys / buttons?
Current License: CC BY-SA 4.0
10 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| May 18, 2020 at 12:10 | history | edited | tlfong01 | CC BY-SA 4.0 |
edited title
|
| Apr 13, 2019 at 4:51 | answer | added | tlfong01 | timeline score: 0 | |
| Apr 12, 2019 at 12:39 | comment | added | tlfong01 | @Ionică Bizău - Yes, I can post a short answer, perhaps over the weekend. BTW, I have a midi keyboard, but I have not idea if the keys are capacitive or else. You might like to read the following about my keyboard and my answer which partly relates to your project - raspberrypi.stackexchange.com/questions/96083/… You might also read the following about mcp23008 based 4 x 4 keyboard design. This design can easily be scaled up using mcp23x17, to 16 x 16 = 256 keys. ww1.microchip.com/downloads/en/AppNotes/01081a.pdf | |
| Apr 12, 2019 at 9:32 | comment | added | Ionică Bizău | @tlfong01 Can you please post an answer with more details? That would be great. Haven't started this project yet. | |
| Apr 12, 2019 at 7:51 | comment | added | tlfong01 | Yes, matrix keypad is the standard configuration. In my Arduino days I DIYed 16 key key pad using single keys connected as a matrix. Then I read MagPi about MCP23008 and found MCP's app notes on how to use MCP23008's two 4bit ports to make a 16 key key pad. That app notes is very good, and I followed the notes and made a keypad, using polling and interrupt. Of course a simple setup is to use 8 Rpi GPIO keys as a 4 x 4 matrix to handle 16 keys. Perhaps I can give an answer here recommending both methods. | |
| Apr 8, 2019 at 15:01 | comment | added | jsotola | set it up as a keypad matrix ...... 8x4 will cover the 32 keys .... 6x6 would allow you to read 36 keys ...... both of these arrangements would require 12 data pins if no external circuitry was used | |
| Apr 8, 2019 at 8:04 | vote | accept | Ionică Bizău | ||
| Apr 8, 2019 at 7:33 | history | edited | Ionică Bizău | CC BY-SA 4.0 |
added 58 characters in body
|
| Apr 8, 2019 at 7:30 | answer | added | joan | timeline score: 1 | |
| Apr 8, 2019 at 7:22 | history | asked | Ionică Bizău | CC BY-SA 4.0 |