Add OPAMP library for Uno R4 (WiFi, Minima) by maxgerhardt · Pull Request #97 · arduino/ArduinoCor... Resolves #23 Adds an OPAMP library for the Arduino Uno R4 WiFi and Minima boards. Portenta C33's chip does not have an OPAMP. Does not rely on Renesas FSP code, writes to OPAMP registers directly, ...

And of course I started a pull-request so that this can be included by standard in the Arduino core :)

Today I wrote a OPAMP Arduino library for the Uno R4 WiFi and Minima. Tested with the function generator and oscilloscope from previous posts. Setup uses a 2x non-inverting amplifier circuit, just using two 10K resistors. Works great! Output at top, input at the bottom.

All that's left to do is to screw it into its acrylic casing and store both function generator and oscilloscope safely. Until next time, where will need both of them in a project involving a yet little-used function of the Arduino Uno R4 WiFi board..

Probing the output of the function generator

A triangle wave

Sawtooth wave

Sine wave

Output is a nice triangle wave. By pressing the button, we can switch between square, triangle / sawtooth and sine wave. The knobs adjust frequency (1Hz-20MHz), amplitude, offset and duty-cycle. All of them look really nice in the oscilloscope, perfect adjustable test signals.

Probe connected to board

Board outputting a signal

REAL MOMENT OF TRUTH. Does the assembled function generator actually output anything or did I screw it all up?? Connecting the probe to the generator's GND and OUT signal and giving it power.. OH YES IT DOES!11

Unpacked Hantek oscilloscope

Oscilliscope connected to calibration port

Measurement of calibration wave

Okay, so now this board is potentially outputting a signal.. but we have no way of seeing that. Time to unpack the Hantek 6022BL oscilliscope, install the drivers and measurement software. Conveniently, the oscilloscope itself has a 1kHz calibration signal that we can use to check if the is working.

First moment of truth. The last IC is put into its socket and my lab bench power supply is set to output the minimum 7V the board needs to power up.. Will it short circuit? Nope, it draws a nice 100mA, with no short-curcuit or explosion! Wohoo!

Start of assembled PCB

Assembled PCB

Component list

And before you know it, a whole evening is spent on meticulously soldering the together the components of the function generator kit. Starting with the smallest and low-profile components and working upwards. Checking off component after component, it starts coming together for a first test...

A DIY function generator kit, unassembled

The bare PCB of the function generator.

The right is a Hantek 6022BL 2-ch. USB oscilloscope, I can look at my analog input and output signals with that. The left is a function generator built around the Maxim MAX038 chip. That will generate a test signal. But, some assembly required.. Soldering iron to the rescue!

Function generator build kit and Hantek oscilliscope

Before we dive into RISC-V in my microblog, a small project came up in between: For a testing a certain mixed-signal application (tba. later), I need two crucial things : An oscilliscope and a function generator. My home electronics lab had neither. But today, a small Amazon package arrived..

Hello, world! Expect some news on my latest electronics hardware and programming projects soon :)
We're going #RISC-V.