07/16/2019 at 19:09 •
I received an email today stating that the project name "LoraSleeve" needs to be changed as it contains LoRa which is a registered trademark of Semtech. This and some other things were the contents of the email. I had to change the project name to something not "LoRa" to avoid the project from being removed from the website.
So, here we are. Skrypt is the term that came to my mind immediately. Why ? I don't know myself. If another name pops up, I'll update appropriately. If you have a suggestion for a name, do well to comment and we'll review it together.
I have been a little busy these few weeks and I'll be back updating the project as it progresses. I have done some hardware tests with modules attached together and we seem to be on the right path.
There might be a need for an android application as I have been using BLE terminal apps and UART over USB OTG for my tests.
05/24/2019 at 05:23 •
It took quite a while for the PCB to arrive from China. Who knew China is that far away from here. The overall build quality of the PCB seems okay but I noticed a little problem. The board was a little bit bigger than what I had in my head and I added too much features for such low-power hardware.
It was probably due to the fact that it is my 4th board (noob alert) and I am still struggling to get my dimensions well. Also because I was a little too ambitious. At the end, I decided to
- Reduce the number of buttons drastically and allow tweaking of parameters via Wifi/BLE.
- Use ESP32 Wroom 32 for the next revision as they seem small enough for what I intend and I have(finally) experience soldering and troubleshooting them.
- Include a LNA and SMA antenna on the board without compromising its size. Probably a removable antenna or something similar.
- Make a repeater with better specs and to reduce the transmission time and power required by LoraSleeve.
- Find a way, if I can, to implement my own RFM96W on board. This does not seem very likely but who knows.
One important reason for switching to ESP32 Wroom 32 is its availability on Aliexpress compared to Esp32 Pico D4. And Aliexpress (3 weeks) seems to ship faster to my place than Lcsc (still waiting).
I am definitely not wasting 40 pieces of PCB (39 is okay). I will definitely populate at least one in the coming week ( when LCSC finally comes through) and will get started on the software.
I will make a log about the new schematic and layout soonest.
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.