That didn't fix a problem, but helped to make a code shorter. Serial.println('Buttons State: Changed: Items to change: Controls thanks for advise. Uint8_t items_to_change = (input & changed) * Fixing, what positions had to be switched */ * Configuration of shift input register 74HC165 */ python raspberry-pi rpi gpio python-library spi wiring. I have never used the 74HC165 so I'm not sure to have CPOL and CPHA correct, but you have to use them in daisy chain (output of first chip connect to input of second chip etc.) and sample them synchrone (tying all SH wires together) code in setup: SPCR (1< 74hc165 hardware spi atmega

Togling was working as it was supposed to work. I've made a mistake in depicturing of 'Controls' state. * Run trough all inputs from shift register */ġ) After pressing button 1: Buttons State: Controls State:Ģ) When it releases: Buttons State: Controls State:ģ) After pressing button 7: Buttons State: Controls State:Ĥ) After its releasing: Buttons State: Controls State:ĥ) After pressing button 1: Buttons State: Controls State:Ħ) When it releases: Buttons State: Controls State:Ģ) After its release: Buttons State: Controls State:Ĥ) After its releasing Buttons State: Controls State:ĥ) After next pressing of button 1: Buttons State: Controls State:Ħ) After its releasing: Buttons State: Controls State: Serial.println('Buttons State: Controls State:') Uint8_t changed = input ^ previous_input

* If anything has ben changed - report to UART */ * Read the inputs from shift register */ Static uint8_t previous_input = 00000000 * Variable to store the Controls state for further transfer */ The response is going to be processe to change variable 'controls', but it doesn't work properly. I'm trying to connect the 74HC165 (8-bit input shift register) to Arduino UNO via SPI to check the state of 8 buttons.