04/02/2019 at 06:26 •
I have known about JLCPCB for a while and thought of giving them a try for this project. The PCB is a small one and to save money I thought of panelizing the PCB. I'll have more PCBs for the same price. YAY. There was only one problem, I had no idea how to go about it. I went off to google and searched. I got a couple of cool options. Some easy and others not so easy.
After deliberating with google and very helpful guys on the HackChat, I settled for GerberTools (https://github.com/ThisIsNotRocketScience/GerberTools/releases). This awesome application has a cool GUI and quite efficient gerber Panelizer. I took me a while to get the hang of it for I had dimensioned my board on the copper layer (yeah, who does that?). I finally got it to work by removing the dimension and using DirtyPCB's cam files on eagle after it turned out that the app was no fan of the .gbr format. Below is the result I got after panelizing
Notice the absence of traces in the bottom layer. Thats a bug I hope the maker of the gerber viewer fixes. I displayed it quite well on JLCPCBs gerber viewer though. Well, I am sure the PCB is very well on its way down and will be available in a few weeks.
NB. I'll update the PCB file again (Sorry)
03/18/2019 at 11:37 •
CORRECTION AND CHANGES TO SCHEMATIC.
It took a while for me to notice a "little" error in the previously posted schematic. I missed a pull up resistor for the buttons and misspelled some net names . Fortunately, I noticed it before starting the layout of the PCB. In my bid to correct the mistake, I thought it wise to review the components used with the device and made the following changes.
- I removed the OLED in a bid to reduce the power consumed and since all that it display could be inferred by other means (via LED and the PC/smartphone itself).
- I reduced the number of buttons to two.
- I added another LED for power and connection indication.
I began laying out the components on the board with the aim of making the PCB as small as possible. There was a limit to its size as I used 0805 components for easy hand soldering ( I can't cope with smaller components ,YET ). I used the ESP32 Pico D4 chip for smaller size. The PCB measured 5 cm by 3.6 cm at the end.
The new schematic and layout has been uploaded in the project page. Off to JLCPCB...
03/14/2019 at 16:50 •
When I created this project page, I had no LoRa module at hand . I still don't, but I had to get started. I checked my stash of unused components, and found a pair of NRF24L01.
An RF transceiver, that is not LoRa.
I played around with its transmission and reception of messages. I used Serial via the Android Arduino application serial console on both phones. It worked, not well enough, but enough to prove a point.
My Android development skill is close to non-existent, and I hope to use Thunkable to make an app that interfaces with the ESP32 Bluetooth and sends and receive message from the hardware.
I began making the schematic diagram early this morning. The device was to have
- A small screen to display basic information like battery level, number of connections etc.
- A rechargeable battery
I used 0805 components and the ESP32 Pico D4. The PCB layout is not complete and I thought I'd share the PDF of the schematic.
This is the progress so far.