Search found 601 matches

by parkview
Wed Jun 22, 2022 8:20 pm
Forum: Projects
Topic: Adjustable USB Power and Measurement Board
Replies: 7
Views: 10561

Re: Adjustable USB Power Profiler Board

Amongst everything else going on, I managed to get the (Now calling it) USB Power Profiler Board sent off to JLCPCB this morning. It ended up being a bit more complex than the V0.6 block diagram, so it should be interesting to see how it turns out. It would be great if it can measure down to the 10'...
by parkview
Tue Jun 14, 2022 12:16 pm
Forum: Projects
Topic: Universal e-Paper Name Badge
Replies: 8
Views: 15214

Re: Universal e-Paper Name Badge

Well, somehow the Australian Postal system lost this and another PCB from JLCPCB during shipping. This was during C19 dark days here in WA, so fair enough. Since the loss, I have discovered two things about this PCB: 1) the WS2812 foot print was wrong 2) the MOSFET driving the e-Paper power was in b...
by parkview
Sun Jun 12, 2022 8:54 pm
Forum: Projects
Topic: ESP32-S3 Dev Board
Replies: 0
Views: 10660

ESP32-S3 Dev Board

I have been hanging out to try a ESP32-S3 MCU. I have been watching stock on LCSC over my last few orders, but none of the WROOM series are listed in stock, so after watching a Unexpected Maker video , I bit the bullet and decided to make my own Dev board. I wanted to have a go at adding SPI based 1...
by parkview
Sat Jun 11, 2022 8:54 pm
Forum: Projects
Topic: Open-PyroJet a 3D Metal/Ceramic Printer
Replies: 13
Views: 13266

Re: Open-PyroJet a 3D Metal/Ceramic Printer

The 2nd version PCB's arrived last week, and I jumped in and assembled them and I think they came out looking really nice: Controller Front: OPJ-Controller_V0.6_sml.jpg Driver Front: OPJ-Driver_V0.6_sml.jpg So the changes between the V0.5 and V0.6 PCB versions are mainly that it now has individual A...
by parkview
Sat May 28, 2022 10:41 pm
Forum: Projects
Topic: Adjustable USB Power and Measurement Board
Replies: 7
Views: 10561

Re: Adjustable USB Power and Measurement Board

Today I did a full path voltage loss measurement across all active components. With a USB 5.03V input and a load of around 490mA I measured a loss of 466.4mA across the voltage regulator path. I measured a loss of 355.6mA with the voltage regulator switched out. Basically it comes down to I loose 58...
by parkview
Thu May 26, 2022 9:12 pm
Forum: Projects
Topic: Adjustable USB Power and Measurement Board
Replies: 7
Views: 10561

Re: Adjustable USB Power and Measurement Board

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...
by parkview
Wed May 25, 2022 3:10 pm
Forum: Projects
Topic: Adjustable USB Power and Measurement Board
Replies: 7
Views: 10561

Adjustable USB Power and Measurement Board

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...
by parkview
Wed May 11, 2022 9:22 pm
Forum: Projects
Topic: Open-PyroJet a 3D Metal/Ceramic Printer
Replies: 13
Views: 13266

Re: Open-PyroJet a 3D Metal/Ceramic Printer

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...
by parkview
Fri May 06, 2022 3:34 pm
Forum: Projects
Topic: Open-PyroJet a 3D Metal/Ceramic Printer
Replies: 13
Views: 13266

Re: Open-PyroJet a 3D Metal/Ceramic Printer

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...
by parkview
Fri May 06, 2022 3:17 pm
Forum: Projects
Topic: Open-PyroJet a 3D Metal/Ceramic Printer
Replies: 13
Views: 13266

Re: Open-PyroJet a 3D Metal/Ceramic Printer

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...
by parkview
Thu May 05, 2022 9:39 pm
Forum: Projects
Topic: Open-PyroJet a 3D Metal/Ceramic Printer
Replies: 13
Views: 13266

Re: Open-PyroJet a 3D Metal/Ceramic Printer

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...
by parkview
Mon Apr 25, 2022 10:09 pm
Forum: Projects
Topic: Open-PyroJet a 3D Metal/Ceramic Printer
Replies: 13
Views: 13266

Re: Open-PyroJet a 3D Metal/Ceramic Printer

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...
by parkview
Mon Apr 25, 2022 9:31 pm
Forum: Projects
Topic: Open-PyroJet a 3D Metal/Ceramic Printer
Replies: 13
Views: 13266

Re: Open-PyroJet a 3D Metal/Ceramic Printer

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 ...
by parkview
Mon Apr 25, 2022 8:41 pm
Forum: Projects
Topic: Open-PyroJet a 3D Metal/Ceramic Printer
Replies: 13
Views: 13266

Re: Open-PyroJet a 3D Metal/Ceramic Printer

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...
by parkview
Mon Apr 25, 2022 8:03 pm
Forum: Projects
Topic: Open-PyroJet a 3D Metal/Ceramic Printer
Replies: 13
Views: 13266

Re: Open-PyroJet a 3D Metal/Ceramic Printer

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:
OPJ-ControllerV0.5.jpg
OPJ-ControllerV0.5.jpg (60.45 KiB) Viewed 12959 times
by parkview
Sun Mar 27, 2022 9:43 pm
Forum: Projects
Topic: Open-PyroJet a 3D Metal/Ceramic Printer
Replies: 13
Views: 13266

Re: Open-PyroJet a 3D Metal/Ceramic Printer - The Printhead

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...
by parkview
Sun Mar 27, 2022 5:32 pm
Forum: Projects
Topic: Open-PyroJet a 3D Metal/Ceramic Printer
Replies: 13
Views: 13266

Re: Open-PyroJet a 3D Metal/Ceramic Printer - The Controller

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...
by parkview
Sun Mar 27, 2022 12:37 pm
Forum: Projects
Topic: Open-PyroJet a 3D Metal/Ceramic Printer
Replies: 13
Views: 13266

Re: Open-PyroJet a 3D Metal/Ceramic Printer - The Driver Board

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...
by parkview
Sun Mar 27, 2022 11:50 am
Forum: Projects
Topic: Open-PyroJet a 3D Metal/Ceramic Printer
Replies: 13
Views: 13266

Open-PyroJet a 3D Metal/Ceramic Printer

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...
by parkview
Tue Mar 08, 2022 4:55 pm
Forum: Projects
Topic: ESP32 Waveform Generator
Replies: 0
Views: 10946

ESP32 Waveform Generator

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...