Flashing/Upgrading the eMMC of Beaglebone Black (2018)

I am looking for instructions on how to upgrade my BeagleBone Black. Most of the instructions on the web are outdated and doesn't work. Here are the steps I did to upgrade my BBB:

1. Download the image from https://beagleboard.org/latest-images
2. Extract using 7-zip and you should be able to have a file with .img extension.
3. Write using Win32DiskImager.
4. As of this writing, there are additional step that needs to be done to enable the eMMC flasher on the image. You need to modify the uEnv.txt
1.  If you have Windows machine, use VirtualBox and load your favorite Linux distro (LUbuntu on my case)
2. Follow these steps extracted from Beagleboard.org:  To turn these images into eMMC flasher images, edit the /boot/uEnv.txt file on the Linux partition on the microSD card and remove the '#' on the line with 'cmdline=init=/opt/scripts/tools/eMMC/init-eMMC-flasher-v3.sh'. Enabling this will cause booting the microSD card to flash the eMMC. Images are no longer provided here for this to avoid people accidentally overwriting their eMMC flash.
5. Make sure that your BBB is turned off.
6. Plug in the SD card.
7. Press and Hold S2 button. (Don't let go!)
8. Plug in the power. 
9. Wait for the User LED to flash then about 4 to 5 seconds, release S2 button
10. Wait for around 10 to 20 seconds for the User LEDs to do "running LED lights". This is the signal that BBB is flashing.
11. Wait for user LEDs to turn off, this is the signal that BBB is finished flashing.
12. It will turn off at the end.
13. Remove power
14. Remove SD card.
15. Reapply power. 
16. Enjoy

Embedded C++ for MSP430 using IAR compiler

In my current project, I used Embedded C++ for MSP430 using IAR compiler. I re-created an existing assembly project and I was able to reduce the code size from 30KB down to 15KB. Yet, I have more features in my new Embedded C++ firmware. I am very careful with the C++ features that I used due to limited resources (processing power, RAM, FLASH size), the most expensive thing that I used is the virtual method which I essentially needed to implement strategy and template method design patterns.  I also used the Instantiator Based Programming Paradigm to eliminate unneeded build times (similar to C++ PIMPL) and to be able to adhere to a good programming principle: "Program to Interface, Not to implementation."

At the end of the project, the code size is small, the code is very expressive, code is unit-testable and the software architecture is very flexible due to application of object-oriented design patterns.

I am very impressed with the IAR C++ compiler.

Unit Testing Simple Linux Kernel Module

This morning, I am trying to learn Linux Kernel development from https://blog.sourcerer.io/writing-a-simple-linux-kernel-module-d9dc3762c234  Link  .

The examples are very good. However, I am looking for a way to do unit testing and I can't find any info on how to do this. I am a unit test advocate and I fully support unit testing. Why? Because system testing is expensive and from my experience, time-consuming.

I would like to unit test on Eclipse so that I could use Eclipse CDT and GDB's full power in terms of debugging.

Eclipse Oxygen.3 CDT Release (4.7.3)

With just a few #defines and #ifdefs, I was able to come up with a way to do simple unit tests using asserts. Nothing impressive actually, however the quick feedback of unit tests will be very helpful in getting good code coverage of testing.

I placed the source code demonstration here: Link

For now this will work, however I will be improving this and will be adding a proper unit testing framework.

My Less than $4 Faucet Temperature Monitor

This weekend, I was able to finish my temperature monitor. 

Faucet temperature monitor (I still need to tidy up the wiring LOL)

I just bought the following materials:
- Temperature display with thermocouple from Ebay ($1.50)
- Crayon box from Walmart ($1)
- Electrical tape

I used my Dremel tool to fit the crayon box into my faucet. All in all, I just spent less than $4.

Easy Arduino unit testing using Emulare and ArduinoUnit

I just uploaded a video on youtube on How to do Unit Testing on Arduino using Emulare and AndroidUnit. This is purely a simulator unit testing and doesn't require a board, which is great for unit testing.

Writing NFC app using Cordova for M24LR16 I2C RFID EEPROM - but...

I am in the process of creating an Android app using Cordova with phonegap-NFC plugin. I am interfacing with an RFID I2C EEPROM M24LR16 and my firmware is already ready and tested. I have the sample Android app of ST Microelectronics and the RFID EEPROM works and I can transfer and read data. But after building the Cordova app for 1 hour, it didn't work.

Digging into the documentation, phonegap-nfc doesn't support non-NDEF tags. Most folks are suggesting to modify the phonegap-NFC library for that purpose. It is my first time to work with NFC tag firmware and this is a very good learning experience. I don't know which path to go as of the moment, but I will try to modify the phonegap-NFC library. If it doesn't work out, I will develop the Android app using Android Studio.

Update:
I had just finished creating the Android app using Java (Android Studio). It works great with Non-NDEF NFC tags. :)

LORA: RF SX1278 Review

This weekend, I did a prototype project using LORA SX1278 for a 433MHz project. A friend of mine sent me two XL1278 module.

When I received the modules, I was so excited to test it. I have experience with TI CC1101/CC430 and NRF905 and I would like to do a comparison in terms of development time.

Upon reading the datasheet, everything is very straightforward. With the SX1278 datasheet's help, I was able to develop my C++ SX1278 driver and make it work with TI MSP430 FRAM microcontroller. Unlike, TI CC1101/CC430, I don't need any tool like SmartRF studio to get all the settings. I can just do a register computation for the frequency. Everything is straightforward with this LORA chip.

Since I don't have a spectrum analyzer, I used my $9 USB RTL-SDR (Software Defined Radio) to capture signals in the air. 

I used Spektrum (link) to see if there are any activities in the air if I transmit something. This Spektrum is pretty basic and it does it's job. I just hope that it would have a hold function like a normal spectrum analyzer (like holding a peak detection). But still, it is a very helpful tool. I don't need to buy a spectrum analyzer. :D

Spektrum Interface (not an actual picture from my experiment)

Continuing with my experiment, when there is no one transmitting, RSSI levels are at -137dBm. I tried transmitting something (I used Spreading Factor of 7 and I am transmitting 128 packets in one shot) and the receiver got a 128byte packet at -19dBm.  That is pretty impressive. I haven't done my Friis equation transmission equation analysis yet but looking at this data, I believe we can achieve very far range with this one.

This is a very good module. However, I may need to try some other antenna and I may need to design a quarter wave monopole antenna by hand before doing our range test.

-Jeff


(I don't own any of the picture, please see the link)
Image from: https://www.ebay.com/itm/433-LoRa-SX1278-Long-Range-RF-Wireless-Transceivr-Module-SX1276-5Km-For-Arduino-/322929644930
https://www.rtl-sdr.com/spektrum-new-rtl-sdr-spectrum-analyzer-software/