Pages: [1]   Go Down
Author Topic: Auxiliary Dashboard for my wife's car  (Read 1682 times)
0 Members and 1 Guest are viewing this topic.
Maryland, USA
Offline Offline
Full Member
***
Karma: 0
Posts: 162
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

I had a vision a little over a year ago to design an auxiliary dashboard to provide reliable time, compass heading & temperature info to my wife's car (which is otherwise rather spartan, being an ex-police cruiser we bought from a local dealer...) and I'm pleased to show off my progress--yesterday I ran the cabling and got the bulk of the system working and installed.

Pictures and details are here: http://spirilis.net/junk/arduino/carnet_install/project.html

Highlights:
  • Uses I2C and OneWire, with I2C being most of the communication
  • Makes use of a "long distance" buffered I2C network employing NXP P82B715 chips on each board to help the devices use the long-distance bus
  • LCD display is a large 16x2 by Newhaven, and I designed my own "I2C backpack" for the board which includes PWM on the LED backlight, ability to cut power to the LCD completely and go into deep sleep (SLEEP_MODE_PWR_DOWN).  The I2C commandset is built around a virtual 8-bit "memory map" implemented by a 256-byte char array on the LCD backpack's ATmega328 firmware, with the upper 16 bytes implemented as special "strobe registers" to carry out actions/configuration updates.
  • I incorporated a DS18B20 temp sensor into every board ... Because I can smiley (and I have a ton of them)
  • ATmega328 used in the LCD backpack, ATmega1284P (Bobuino) currently used for the controller before I can build something permanent for that.  Arduino IDE used for both firmwares.
  • Future plans for this system include a Keyless entry system based on the nRF24L01+ and Sparkfun's nordic keyfobs.

Still need to run a cable under the hood/behind the bumper for proper ambient temperature, which is my next task before designing a control box w/rotary encoder for the dashboard.
« Last Edit: June 19, 2012, 09:08:18 pm by spirilis » Logged

Tacoma, WA
Offline Offline
Full Member
***
Karma: 4
Posts: 192
Arduino rocks
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

Not bad. Probably the best looking home made board I can recall seeing. Might be time to step up to one of the budget professional options though.
Logged

Brian from Tacoma, WA
Arduino evangelist - since Dec, 2010.

Greenville, IL
Offline Offline
Edison Member
*
Karma: 15
Posts: 1330
Warning Novice on board! 0 to 1 chance of errors!
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset


 Nicely done! You have put a lot of work and thought into that project for sure! The fact that you have your project in place and working is a great accomplishment!
Logged


Maryland, USA
Offline Offline
Full Member
***
Karma: 0
Posts: 162
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

Humm, weird, went outside this morning and found it in key-off mode (as expected) but with the time 22 minutes slow.  I figured maybe the arduino crashed or something, so I disconnected & reconnected it and it updated--time advanced by 1 minute, but still 21 minutes slow.  I ran that system in my basement with the ChronoDot supplying the time for weeks without a hitch so I'm very curious what's gone wrong.  The ChronoDot (Maxim DS3231 breakout board w/ coin cell battery) is supposed to lose no more than 1 minute per year.

Alas, didn't have time to troubleshoot beyond that.  Will have to pick this up later in the evening.


On second thought, I think it's condensation.  I noticed lots of condensation on the rear window so it's a good likelihood there is condensation in the trunk.  Didn't even think about that when I designed everything.  The paint "soldermask" on the boards should help prevent some shorts, but I suspect I should stick a packet of dessicant in the sensor board housing or maybe apply paint to the pins of the DS3231 chip and exposed header solder joints to shore that up a bit more.  Better than trying to pot the whole thing...
« Last Edit: June 20, 2012, 08:49:49 am by spirilis » Logged

nr Bundaberg, Australia
Offline Offline
Tesla Member
***
Karma: 129
Posts: 8602
Scattered showers my arse -- Noah, 2348BC.
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

Nicely done and the first time I've seen those I2C buffer chips used for real.

______
Rob
Logged

Rob Gray aka the GRAYnomad www.robgray.com

0
Offline Offline
Jr. Member
**
Karma: 2
Posts: 96
There are two ways to write error-free programs; only the third one works.
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

beautiful finished product, but I would leave the PCB laying on the dash it looks so nice  smiley-lol
Logged

"#define QUESTION ((bb) || !(bb))  - Shakespeare."

South Texas
Offline Offline
Edison Member
*
Karma: 8
Posts: 1025
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Sorry, but I have to ask - Is your wife as thrilled with it as you are, or does she roll her eyes and shake her head over "that" project?
Logged

Maryland, USA
Offline Offline
Full Member
***
Karma: 0
Posts: 162
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

Haha, she likes it, but she wasn't half as excited about it as I was smiley-wink
She keeps getting the urge to say "GO GO GADGET!" every time she steps in...
Logged

Maryland, USA
Offline Offline
Full Member
***
Karma: 0
Posts: 162
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

FWIW, suspecting condensation in the morning had something to do with the time lapse, I took the sensor board out last night and applied silicone dielectric tune-up grease to the SMD RTC chip's leads (the DS3231) and various other solder joints on the sensor board.  This morning the time was spot-on (with plenty of condensation all over the car, didn't check the trunk but it was probably there too.)
Logged

Pages: [1]   Go Up
Jump to: