South West Makers

The first version of the Adjustable USB Power and Measurement board had this kind of block diagram: V0.5_Block-Diagram.jpg When I designed this, I didn't realise how slow i2C reading was on a ESP32. To save GPIO, I used i2c based INA219, which has a maximum of one thousand Samples per Second. I woul...

As you can see from this Forum, I have been working on a number of ESP32 based projects. It would be really handy to be able to have a USB based power limiting function and at the same time, be able to measure power being used at high speed, say at least 20K Samples Per Second (SPS). This would help...

It's been another busy week. Both the Controller and Driver board designs have been updated and the files have been sent off for manufacture with a Blue solder resist: Driver Board: i2C121 IC removed and replaced with the ADC128, an 8-channel SPI based Analogue to Digital Converter IC removed the MA...

Stephen was very kind and let me pop over to his house at short notice and record some Rigol 140MHz bandwidth scope photos. Just to show whats happening at a much higher bandwidth and cleaner view of the 30V Motor driver voltage line: 30V-line-pulse-cap-charge_sml.jpg Above the Yellow line is the MA...

First up, here is a scope shot of the ADC121 input pin with a 100nF capacitor across it to ground: DAC-ADC-Data.3.jpg It looks much cleaner doesn't it! I then had a play with reading and setting the ESP32 i2C clock frequency. I also checked it with the scope. I have a i2C based OLED screen on the bu...

After spending way too long (I am not a coder), digging through the ArduSat ADC121xx functions and code, I managed to write out some simple low level i2C function to read the ADC121 IC. Unfortunately it had an extra buggy line that was causing the i2C read to fault, is it was asking it to restart tr...

As I have mentioned above, the TM18870 motor driver IC comes with the option to limit the motor (filament in our case) current. You can program this via the sense resistor, or varying the IC reference voltage. I have the Vref set to 3.3V, as it's already on the PCB and saves hosting a special LDO fo...

The print head PCB has been stuck in the Perth postal system for some time now, luckily Michael sent me his self assembled Gen 2 printhead that's built around 2.54mm and 1.27mm perf board. Basically the SiC filament is carefully kapton taped into place and sandwiched between the two board which are ...

The Driver parts eventually arrived and I assembled the board the same day, here it is cooking on the hotplate: OPJ-Driver-hotplate.jpg The large back inductor took the longest due to it's thermal mass, but everything came out well. I hand soldered on the rest of the missing large 2512 resistors - o...

The PCB's arrived quickly due to priority DHL Express shipping. So fast, that the parts from LCSC hadn't arrived yet. Still, it gave me time to assemble the simple Controller board and write some basic Arduino based testing software. So far so good:

So previously the experimental printheads have been constructed out of 2.54mm and 1.27mm perf board fiberglass PCB's. It was a very cheap build, but took a while to assemble correctly. While designing the two Driver and Controller boards, I pondered how difficult it would be to design a printhead ou...

Due to the silicon shortage, we are doing the initial trials with the venerable ESP32-WROOM-32D/E module. These are cheap and available and come with WiFi and we all have used one before in other projects. If we need more GPIO pins we could move to the ESP32-S2, or later (if/when they become availab...

I put my hand up to have a go at designing up an experimental set of PCB's to help explore different printhead designs. It started off as one PCB, but ended up being a double set, one being a driver board and the other a controller board based on a ESP32. This post is about the Driver board. One pro...

On the Espressif Discord channel a few weeks ago there was an announcement by Michael, the originator of a project that is attempting to build a cheap Open Hardware based 3D printer that can print out metal and ceramics etc. As of today, there are people from USA, Europe and Australia helping out on...

Last Saturday Hack-a-Day posted this interesting project by Debraj: https://hackaday.com/2022/03/05/low-cost-two-channel-scriptable-waveform-generator/ (check out his video) I looked up the IC's he used and pondered what could be done using a ESP32. I had already found some ESP32 code to generate fr...

We have tested quite a few cheap Chinese robots and found each one missing a feature or two that we would like, so a couple of us are having a go at designing a Micro Robot. This will be Raspberry Pi based, but hosts an ESP32-Pico MCU to help out with monitoring and controlling things. Initial Featu...

This H-a-D project popped up last week . It made me think about the remotes we have scattered around the house. We love our Streaming movies/shows etc, so we have a mobile phone on hand, so wouldn't it be handy to be able to control the TV via your mobile phone? Way back when I purchased a dongle fo...

The first PCB arrived back from JLCPCB, China last week. I quickly assembled the board, but had no end of trouble getting the ESP32-Pico MCU aligned and correctly into place. I even managed to burn the MCU out and the 1A LDO! I had another crack at it yesterday and found that the LDO had burnt out a...

While waiting the three or so weeks for the PCB's to arrive back from JLCPCB, I started working on the software. I used my Arduino Sensor Training Board as it had a similarly designed MEMS microphone and MPU. Enough so that I could test out some Arduino code. I based my initial version on Eric's Git...

This YT Video popped YT Video popped up in early Jan 2022. I love the way the particles flow when he blows on the microphone. Some days later one of us mentioned a (new to me) Open Source gaming engine called Godot. I thought it would be fun trying to replicate the particle project in the Godot engi...