EEVblog Electronics Community Forum

Electronics => Repair => Topic started by: 2X on May 22, 2020, 08:18:49 pm

Title: 3 Digits Seven Segment Voltmeter - Driver Chip
Post by: 2X on May 22, 2020, 08:18:49 pm

Hello,
I have the below voltmeter but doesn't measuse (it lights only two segments). The 5V voltage regulator works ok at the back of the PCB. The chip has erased the letters on it and I don't have any part number to check it or replace it. Does anyone knows what is this chip/part number (or it is a microcontroller)?

Title: Re: 3 Digits Seven Segment Voltmeter - Driver Chip
Post by: Gyro on May 22, 2020, 08:23:15 pm

Yes, it's likely to be a programmed microcontroller, using the on-chip ADC.

Title: Re: 3 Digits Seven Segment Voltmeter - Driver Chip
Post by: coromonadalix on May 23, 2020, 02:54:17 am

even if you have the chip,  you will need the firmware to program it ??  and a way to connect it to a programmer ??     and thess display are sold pretty cheap nowadays ...

Title: Re: 3 Digits Seven Segment Voltmeter - Driver Chip
Post by: 2X on July 04, 2020, 10:31:52 pm

Finally I bought the below from ebay.

https://www.ebay.com/itm/0-28-3-Wire-LED-DC-0-100V-Voltmeter-Digital-Display-Voltage-VOLT-METER-12V-24V/173240751862?ssPageName=STRK%3AMEBIDX%3AIT&var=471952596263&_trksid=p2057872.m2749.l2649 (https://www.ebay.com/itm/0-28-3-Wire-LED-DC-0-100V-Voltmeter-Digital-Display-Voltage-VOLT-METER-12V-24V/173240751862?ssPageName=STRK%3AMEBIDX%3AIT&var=471952596263&_trksid=p2057872.m2749.l2649)