attiny13a
💾 MAX7219 8x8 LED Matrix
250 Bytes
Supports scrolling text effect and custom graphics - stored in flash
💾 LED - ISR
Example of using timer interrupt to control LED
These UART codes were tested on bluetooth (baud 9600) module HC-06, no noticeable loss
💾 UART - Polling and ISR
Rx/Tx 'echo' example (140 bytes) based on AVR305 but :
- Can handle whole strings rather than just 1 byte
- Stores data in RAM, null terminated
- Loops receiving bytes until 0x0D is detected, marking end of string
- Tx routine loops over bytes in RAM until nullbyte marking end of string
- ISR version handles all chars/bytes inside interrupt routine
💾 UART - SPM
This allows you to write to flash memory via bluetooth.
It is useful when you need more than the 64 bytes of RAM.
(make sure you have set the fuses first to allow writing to flash via SPM)
- UART 'mode' triggered by PCINT, ends after x ms
- Data sent in (max) 32 byte chunks during this mode is appended to flash (no overwrite)
- Chunks smaller than 32 bytes will result in RAM trash written to flash (so send that chunk last)
- 32 byte size is due to SPM limited to 32 byte pagesize on attiny13a per execution
- Code reserves 400 bytes flash for writing but this can be increased / decreased
- After every SPM attiny sends back flash contents for verification