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  • Author Author: tariq.ahmad
  • Date Created: Date Created
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DIY Miniature Multimeter -- Episode 483

 

Breadboarding is often the start of great projects but measuring on Breadboards is often not so great. The standard multimeter leads don't fit into breadboard holes and alligator clips are needed to connect to the circuit. There must be a better way! Clem designs a tiny Multimeter dedicated to be used with a breadboard! Easy to connect, battery powered and it even has a WI-FI so you can view the readings on your phone!

 

Get the PCB here: https://aisler.net/p/BKDRSPYV

Bill of Material:

Product Name Manufacturer Quantity Buy Kit
BAK Rechargeable Battery, 3.7 V, Lithium Polymer, 370 mAh, Connector BAK 1 Buy Now
MIDAS Graphic OLED, 96 x 16 Pixels, White on Black, 3V, I2C, 33mm x 10mm, -40 °C Midas 1 Buy Now
MCM Wire Kit, Jumper, Copper, 0.6 mm Diameter, 350 Piece MCM 1 Buy Now
FTDI Interface Analog Development Board LC234X, USB to UART Bridge FTDI 1 Buy Now
MICROCHIP Battery Charger for 1 Cell of Li-Ion, Li-Pol battery, 6V input, 4.2V / 500mA charge, SOT-23-5 Microchip 1 Buy Now
MICROCHIP Fixed LDO Voltage Regulator, 2.1V to 6V, 210mV Drop, 3.3V/500mA Out, SOT-223-3 Microchip 1 Buy Now
ESP32-S2-WROOM espressif 1 Buy Now
USB Connector, USB Type C, USB 3.1, Receptacle, 24 Ways, Surface Mount, Right Angle Molex 1 Buy Now
INA219 SOIC TI 1 Buy Now
0,1 Ohm current shunt resistor panasonic 1 Buy Now

 

Additional Parts:

 

Product Name
ESP32-S2-WROOM
Attachments:
MiniMultimeter_Resources.zip
element14 presents
DIY Miniature Multimeter

element14 Presents  |  About Clem  |  Project Videos

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  •   VERY cool.  Outside my current skill set, but awesome none the less.  Definitely bookmarked for visiting again later.

    On the MODE Resistance in the code, why ADC?  I don't understand why (ReadADC/10).  Wouldn't VR1 = [(Vin/1023) * ReadADC]?  I can understand the rest - although I did need to get out the paper and pen to dust the cobwebs from my brain.

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  •   VERY cool.  Outside my current skill set, but awesome none the less.  Definitely bookmarked for visiting again later.

    On the MODE Resistance in the code, why ADC?  I don't understand why (ReadADC/10).  Wouldn't VR1 = [(Vin/1023) * ReadADC]?  I can understand the rest - although I did need to get out the paper and pen to dust the cobwebs from my brain.

Children
  • in reply to kmikemoo

    well....

    as stated in the video that section gives me headachse, I tried multiple versions and that yielded the closest to the nomainal value of the resistor Imeasured, but my math could be totally wrong, I derived that section from some adc tutorial, and tried to adapt it.

    so if you have abetter understanding please feel free to improve the code.

    one thing I recently heard a lot is that the esps adc is not reliable so there might be another issue.

     

    on a future version I would likely outsource that to a dedicated adc chipp that feeds data back over i2C