DIY Vehicle Speed Sensor Buffer
Here's the riveting tale of how I created a Vehicle Speed Sensor (VSS) interface circuit for my Jeep Grand Wagoneer (yeah, that Jeep).
Speed sensors are used by cruise control systems and by fuel injection computers. Jeep used one for the former.
I wanted the sensor for the GM throttle body injection (TBI) system I retrofitted onto the Jeep's old AMC 360 c.i. V8.
Back when my Jeep was built, vehicle speedometers were driven by a flexible steel cable, the speedometer cable, connected by a tiny gear to the output shaft of the transmission.
Jeep, as with other vehicles of the era, split the speedo cable in half and stuck the VSS in between.
So, with insufficient hobby funds to buy an expensive, off-the-shelf Vehicle Speed Sensor/Buffer, but wanting to reap the benefits of a VSS, I created my own interface. Here's how it went down...
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| Jeep VSS |
I wanted the sensor for the GM throttle body injection (TBI) system I retrofitted onto the Jeep's old AMC 360 c.i. V8.
Back when my Jeep was built, vehicle speedometers were driven by a flexible steel cable, the speedometer cable, connected by a tiny gear to the output shaft of the transmission.
Jeep, as with other vehicles of the era, split the speedo cable in half and stuck the VSS in between.
So, with insufficient hobby funds to buy an expensive, off-the-shelf Vehicle Speed Sensor/Buffer, but wanting to reap the benefits of a VSS, I created my own interface. Here's how it went down...
MONDAY, NOVEMBER 28, 2016
Teaching Programming to Kids (Cont'd)
After much struggle to select a microcontroller and programming system for teaching programming to my 5th grade club, everything suddenly came together.
In a flash I remembered PICAXE, which are low cost BASIC-programmable microcontrollers.
Even better, since all the kids have Chromebooks, PICAXE can be programmed with a Chrome App using the Google Blockly graphical programming framework.
For example, an LED blinky program looks like this:
As pointed out by my SHARC pals during a lunch discussion, 5th graders aren't expert typers so this kind of graphical block system sidesteps a lot of frustration. And I feel this system is better suited for robotics than native Scratch is.
The PICAXE Blockly IDE has some neat features.
First, the IDE includes a simulator so kids can run their code safely before trying it on the robots.
Second, they can see the BASIC language program by clicking a tab so they can get an introduction to standard programming languages.
My sample PICAXE-14M2 is now successfully blinking an LED on pin B.5. Soon I'll be prototyping motor control using the Pololu DRV8835 driver breakout boards I bought during the Black Friday sale.
And, I'm almost done designing a baseboard, similar to my PIPduino, that uses a Pololu step-up/step-down regulator (S10V4F5) for power, also a Black Friday purchase.
Since the PICAXE programmer cables are too costly for our budget I'm going to find or make cheap FTDI breakout boards or else put an FTDI and USB connector onboard.
It feels good to have finalized the MCU and programming system for the kids' robots. I'll order the baseboards soon and hopefully I won't have screwed up anything so we can get started programming in 2-3 weeks.
In a flash I remembered PICAXE, which are low cost BASIC-programmable microcontrollers.
Even better, since all the kids have Chromebooks, PICAXE can be programmed with a Chrome App using the Google Blockly graphical programming framework.
For example, an LED blinky program looks like this:
As pointed out by my SHARC pals during a lunch discussion, 5th graders aren't expert typers so this kind of graphical block system sidesteps a lot of frustration. And I feel this system is better suited for robotics than native Scratch is.
The PICAXE Blockly IDE has some neat features.
First, the IDE includes a simulator so kids can run their code safely before trying it on the robots.
My sample PICAXE-14M2 is now successfully blinking an LED on pin B.5. Soon I'll be prototyping motor control using the Pololu DRV8835 driver breakout boards I bought during the Black Friday sale.
And, I'm almost done designing a baseboard, similar to my PIPduino, that uses a Pololu step-up/step-down regulator (S10V4F5) for power, also a Black Friday purchase.
Since the PICAXE programmer cables are too costly for our budget I'm going to find or make cheap FTDI breakout boards or else put an FTDI and USB connector onboard.
It feels good to have finalized the MCU and programming system for the kids' robots. I'll order the baseboards soon and hopefully I won't have screwed up anything so we can get started programming in 2-3 weeks.
WEDNESDAY, NOVEMBER 23, 2016
Black Friday / Cyber Monday
Here's a list of sales you'll want to check out this Holiday:
Pololu Black Friday - already started! And an awesome sale with great deals once again. My order is placed :) Switching power supplies, robots (Zumo, 3pi, and the new Romi chassi); IR rangers from Sharp, Polou, and a time-of-flight breakout; wheels, motors, motor controllers, the cool A* ATmega32U4 controllers, and lots, lots more. Plus freebies and free(ish) shipping.
Sparkfun Black Friday / Cyber Monday - a wide range of items on sale this year. I'm eyeing the ESP8266 boards, MicroView, as well as the HackRF and RockBLOCK Iridium SatComm module. The FLiR Lepton board is on sale too.
BGMicro has a sale going right now, too. Take 10% off your ENTIRE order by using the code TTM at checkout through 11/23.
Pololu Black Friday - already started! And an awesome sale with great deals once again. My order is placed :) Switching power supplies, robots (Zumo, 3pi, and the new Romi chassi); IR rangers from Sharp, Polou, and a time-of-flight breakout; wheels, motors, motor controllers, the cool A* ATmega32U4 controllers, and lots, lots more. Plus freebies and free(ish) shipping.
Sparkfun Black Friday / Cyber Monday - a wide range of items on sale this year. I'm eyeing the ESP8266 boards, MicroView, as well as the HackRF and RockBLOCK Iridium SatComm module. The FLiR Lepton board is on sale too.
BGMicro has a sale going right now, too. Take 10% off your ENTIRE order by using the code TTM at checkout through 11/23.
- Click Here To Check Out The Items On The Wholesale Page
- Click Here to Check Out 1/2 Price PICs
- Click Here To Check Out The Items On The Pack Page
Parallax has a sale going too. Save $30 or more on:
Newark has tons of overstock stuff for sale
- Scribbler 3 (S3) Robot
- Arduino Shield-Bot Kit
- BlocklyProp Starter Kit [This looks cool; I'm considering Blockly for my 5th graders]
- ELEV-8 v3 Quadcopter Kit
- ELEV-8 v3 Quadcopter Starter Pack
Trossen robotics:
Newark has tons of overstock stuff for sale
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