Cheap and Simple WiFi with ESP8266 for the FRDM Board


How cool would it be to add WiFi support to any projects or IoT? Why not using WiFi with a microcontroller which has only few KBytes of RAM and FLASH. For less than US$5? Dreams came true, and intrigued by an article at Hack-A-Day, I searched a supplier for that ESP8266 module. And this evening I have found the four ESP8266 modules I have ordered for $4.50 each from ElectroDragon in my mailbox. Of course I did not want to wait for the week-end, so I hooked it up to my FRDM-KL25Z board.

ESP8266 Module

ESP8266 Module for US$ 4.50

Continue reading

How NOT to Solder Headers on a Board


There are two basic strategies in teaching:

  1. Teach and show how things should be done.
  2. Teach and show how things should NOT be done.

I usually do the first method. But there is a lot of value in the second method too!

When I asked all student groups to solder the headers on the Freescale FRDM-KL25Z board, I received one report that the board does not work any more. A quick inspection of the board showed this:

Soldering the FRDM Board Headers

How NOT to Solder the FRDM Board Headers

Continue reading

Enabling/Disabling FXOS8700CQ Device Needs a Delay


Found an interesting behaviour with the Freescale FXOS8700CQ on the new Sumo Robots (see “Sensor and Communication Shield for Sumo Robot“): when enabling the accelerometer/magnetometer, it actually did not work:

Failed to Enable FXOS8700 Accelerometer

Failed to Enable FXOS8700 Accelerometer

Continue reading

My First DIY Smoked Beef Brisket: Day 2 – the Way and the Result


Sunday morning started at 7am in a good way: I think the sun guessed already that I want fire up my smoker today.

Morning Ready to Smoke

Morning Ready to Smoke

:!: And no, that’s not the smoker in that picture! That’s ground fog in the morning (see “Inversion“).

Ready to continue my week-end project: DIY Smoked Beef Brisked!

Continue reading

User Interrupt on NMI Pin with Kinetis and ExtInt Component


While my beef brisket (see “My First DIY Smoked Beef Brisket: Day 1“) is smoking on ;-), I have time to investigate a problem I was running on in my lecture on Friday: For the Joystick shield (see “JoyStick Shield with the FRDM Board“) on the FRDM-KL25Z board, I wanted to use an interrupt if I press the green button:

No Interrupts for Button C

No Interrupts for Button C

However, that did not work :-(.

Continue reading

My First DIY Smoked Beef Brisket: Day 1 – Preparation


Ahhhh, I truly love the Texas BBQ (see “BBQ Smoker Monitoring Robot“)! And what I love the most is Beef Brisket. Unfortunately, I cannot travel each time to the US to get some brisket. So good or bad, I have to make the brisket myself :-). The challenge is that outside of Texas, ‘Brisket’ probably is an unknown thing, especially in my area. In the usual grocery stores and supermarket, if I ask for a brisket, they they just shake their heads and ask “brisket what?”. Of course, my local butcher (Messerli, Metzger meines Vertrauens!) in Steinen knew exactly what I need for a Brisket :-): a special cut of beef from the lower chest of beef.

On Tuesday, I sent my wife to pre-order my cut of beef, and this morning we picked it up in the butcher’s store. An excellent piece, already trimmed, 1.662 kg:

Raw Beef Brisket

Raw Beef Brisket

Continue reading