Archive for the 'Propeller' Category

Raspberry Pi B+ with RoboPi

Tuesday, July 29th, 2014

RoboPi works on the new Model B+

I received my Raspberry Pi Model B + boards just a short while ago, and after admiring the four USB ports, mounting holes and better power regulation, I wanted to find out how my boards would work with it.

I tested EZasPi and Pi Jumper quickly – they worked… but I had to wait to find time to test RoboPi. Today I had time, and I am glad to report that RoboPi works well on the Raspberry Pi Model B +

RoboPi running on Raspberry Pi Model B +

(click on the image for a larger version)

I used one M3 18mm+6mm standoff to support RoboPi – while there was no mounting hole for it, there was space for the spacer to sit. I also added a nylon screw in the other RoboPi mounting hole, which provided insulation between RoboPi and one of the two dual USB sockets.

Just to be safe, I added some paper on top of the second dual USB jack – which will be replaced with electrician’s tape.

RoboPi on Raspberry Pi Model B +

(click on the image for a larger version)

As you can see, just like EZasPi, RoboPi is offset roughly 9mm due to the change in the header position.

This actually works out well for the LCD display cable connector.

RoboPi on Raspberry Pi Model B +

(click on the image for a larger version)

I had no problems programming RoboPi, and running demo code, with my Model B+ … RoboPi is definitely quite usable with the B+!

Related Links:

RoboPi readDistance()

Monday, June 30th, 2014

I’ve updated the RoboPi User Manual to v0.81, to match the current API (and firmware) release levels.

Elf RoboPi + Raspberry Pi Robot @Mikronauts http://Mikronauts.com/

This update consists of

  • documents the final version of the Spin API and Pi library readDistance()
  • provides wiring instructions for using supported ultrasonic range sensors
  • updates the tested/working status for the supported sensors

Supported sensors:

  • Parallax Ping
  • SeeedStudio SEN136B5B
  • HC-SR04

You can find the updated documentation on the RoboPi product page at

http://www.mikronauts.com/raspberry-pi/robopi/

Servo Power

Saturday, June 21st, 2014

Now that HexPi has all his hair servo extensions, I’ve decided I need to make a better power distribution board for TBMST than my first effort (shown below) for the NiCd R/C battery packs.

This time, I plan to use an ATX power supply with separate power feeds for servos 1-8, 9-16 and 17 & 18 as the next experiment. It will be interesting to see if the MG-995′s behave better with more instantaneous current being available.

I also made two modified servo extension cables that allow me to replace the power from the servo connector with external power so I can use the normally Pi 5V powered servo connectors with the ATX supply.

RoboPi can already accept separate power sources for the two servo banks (P0-7 and P8-15) on the svt2 and svt3 headers.

The Better Mousetrap Servo Tester @Mikronauts http://Mikronauts.com/

 (click on image for larger version)

I’ll be posting the results of this latest experiment as they become available!

HexPi gets shoes!

Wednesday, June 18th, 2014

I finally had time to work some more on HexPi.

I added 50cm extensions to all the servos, cleaned up the wiring, and gave HexPi three pairs of new shoes!

HexPi @Mikronauts http://Mikronauts.com

(click on the image for a larger photo)

For about what I just added, and the whole build log, please click on the HexPi link below:

Related Links:

Hantek 1008B Oscilloscope Review

Tuesday, June 17th, 2014

Some time ago I purchased a Hantek 1008B USB Oscilloscope specifically for high speed monitoring of up to eight analog channels. I decided to set it up to help me with HexPi and TBMST, as I’ve found my 100MHz/1Gsps scope’s two channels to be too limiting for the multi-channel tests I wanted to run.

I thought teachers, students and hobbyists might find a review useful:

http://www.mikronauts.com/reviews/hantek-1008b-oscilloscope/

At <$100 shipped, it turns out to be a bargain.