Troubleshooting

In the Bus Number Display
Problem:
The Keypad display isn’t work, because using:
1. Wrong type of seven-segment display
2. Wrong type of transistor
Solve method:
1. Replace to common anode type of seven-segment display
2. Replace to PNP type transistor
　

In the Keypad
Problem:
The display can’t display the Key”2” and “6”, because missing a wire.
Solve method:
Redraw the wire between the switch of “2” and “6”
　

In the Main (Bus)
Problem:
1. No output signal of the IC (TP5088)
2. Have much noise in transmit the signal
Solve method:
1.Reconnect the all ground to TP5088
2.Use Common ground of the Main circuit (Bus) and FM transmitter


In the Main (Bus stop)
Problem:
1. Not Sure the IC (MT8870) circuit work properly.
Solve method:
1. Use the following circuit to test

In the Program
Problem:
Confuse of declaration: REG & EQU
Solve method:
The EQU is used to label a value or address only.
But REG is used to register a address, this function is same as setting a address to be a register.