| Problem | Reason | Solution |
|---|---|---|
| Nothing is displayed on the LCD. | The LCD is not connected. | Attach the 34-pins cable between the to 34-pins headers on the STK502. |
| The LCD is not enabled in the AVR device. | Check the LCD initialisation 1 | |
| The update frequency is not correct. | Verify that the clock prescaling correspond with the clock source1. | |
| Some segments on the LCD seems to be stuck at high/low. | The PORTA/C/D and/or G are connected to something else than the LCD display. | Check that nothing is connected to these PORTS on the STK500 and STK502. |
| Can’t control PORTF[1:0] | PF[1:0] is not connected to the ATmega169. | Set the PF[1:0] switch in the PIN-position. |
| Serial Programming does not work | ISP cable not connected. | Connect the ISP cable according to Figure 1. |
| STK500 target voltage error. | Refer to the ATmega169 datasheet for the Serial Programming Voltage limits. Adjust the target voltage on the STK500 board accordingly. | |
| The RSTDISBL Fuse is programmed. | Use Parallel Programming to unprogram the RSTDISBL Fuse. | |
| Parallel Programming does not work. | Cables not connected properly. | Refer to Figure 1 for correct Parallel Programming setup. |
| STK500 target voltage error. | Refer to the ATmega169 data sheet for the Parallel Programming Voltage limits. Adjust the target voltage on the STK500 board accordingly. | |
| The TOSC switch is not correctly set. | Set the TOSC switch in the XTAL-position. | |
| No programming works. | The RESET-signal is not connected to the ATmega169. | Connect PG5 and RST with a jumper. See RST. |
See the application note "AVR065: LCD Driver for the STK502 LCD" on how to control the LCD-display or the the application note "AVR064: STK502 – A Temperature Monitoring System with LCD Output".