Go Back   EcoModder Forum > EcoModding > Fossil Fuel Free
Register Now
 Register Now
 

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 07-30-2014, 04:00 PM   #861 (permalink)
PaulH
 
MPaulHolmes's Avatar
 
Join Date: Feb 2008
Location: Maricopa, AZ (sort of. Actually outside of town)
Posts: 3,832

Michael's Electric Beetle - '71 Volkswagen Superbeetle 500000
Thanks: 1,362
Thanked 1,202 Times in 765 Posts
The power section is identical in this case. What is the normal output voltages for tx and rx for the outside world? I've never checked.

__________________
kits and boards
  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 07-31-2014, 01:03 AM   #862 (permalink)
Dreamer
 
Join Date: Nov 2013
Location: Australia
Posts: 350
Thanks: 95
Thanked 214 Times in 151 Posts
Quote:
Originally Posted by MPaulHolmes View Post
The power section is identical in this case. What is the normal output voltages for tx and rx for the outside world? I've never checked.
Wiki says "Valid signals are either in the range of +3 to +15 volts or the range −3 to −15 volts with respect to the ground/common pin; consequently, the range between −3 to +3 volts is not a valid RS-232 level."
However some devices won't work with levels as low as +- 3v.
Normally there would be a MAX232 chip or equivalent in the circuit that takes logic voltage levels and makes the +- 12v signals.
I think flores would like access to the logic level (3.3v) rather than the +-12v.
So maybe a header with the logic level rx, tx and gnd seperate to the header with the rs232 compatible +- 12v signals.
  Reply With Quote
The Following User Says Thank You to Astro For This Useful Post:
MPaulHolmes (07-31-2014)
Old 07-31-2014, 08:17 AM   #863 (permalink)
PaulH
 
MPaulHolmes's Avatar
 
Join Date: Feb 2008
Location: Maricopa, AZ (sort of. Actually outside of town)
Posts: 3,832

Michael's Electric Beetle - '71 Volkswagen Superbeetle 500000
Thanks: 1,362
Thanked 1,202 Times in 765 Posts
Flores, so you put the resistor divider on the RX and TX pins of the micro, and not on the lines that actually leave the board? Or was on the lines that leave the board? So, If I use the pins that are leaving the board, the separate header would need a voltage divider that goes from 12v down to 3.3v? And if I just bypass the MAX232, the divider would have to go from 5v down to 3.3v?
__________________
kits and boards
  Reply With Quote
Old 07-31-2014, 08:43 AM   #864 (permalink)
EV Connoisseur
 
Join Date: Aug 2010
Location: Amsterdam
Posts: 309
Thanks: 70
Thanked 109 Times in 90 Posts
yes yes.. If it was for me the max232 could be left out... dont no need for rs232 with the raspberry

And actually only the tx is an output so that would need a voltage divider. The rx is a input so no divider on that, 3.3 will trigger a pulse.. a voltage divider would make the signal to weak.
  Reply With Quote
The Following User Says Thank You to flores For This Useful Post:
MPaulHolmes (07-31-2014)
Old 07-31-2014, 09:40 AM   #865 (permalink)
PaulH
 
MPaulHolmes's Avatar
 
Join Date: Feb 2008
Location: Maricopa, AZ (sort of. Actually outside of town)
Posts: 3,832

Michael's Electric Beetle - '71 Volkswagen Superbeetle 500000
Thanks: 1,362
Thanked 1,202 Times in 765 Posts
I'm almost done adding a new connector with voltage divider. So, Flores' rx pin coming from off of the board goes straight to the microcontroller, and is going to be a well behaved 5v signal? Or do I have Flores' RX signal from off the board go to the max232? And the tx signal coming from the microcontroller to off of the board will be a 3.3v, skipping the max232 altogether.
__________________
kits and boards

Last edited by MPaulHolmes; 07-31-2014 at 09:51 AM..
  Reply With Quote
Old 08-01-2014, 04:27 AM   #866 (permalink)
EV Connoisseur
 
Join Date: Aug 2010
Location: Amsterdam
Posts: 309
Thanks: 70
Thanked 109 Times in 90 Posts
Yes skip it.... the raspberry outputs 3.3v so that must NOT go to the max232.. must be connected directly to the micro.
  Reply With Quote
Old 08-01-2014, 04:31 AM   #867 (permalink)
PaulH
 
MPaulHolmes's Avatar
 
Join Date: Feb 2008
Location: Maricopa, AZ (sort of. Actually outside of town)
Posts: 3,832

Michael's Electric Beetle - '71 Volkswagen Superbeetle 500000
Thanks: 1,362
Thanked 1,202 Times in 765 Posts
But RX still goes to the max232?
__________________
kits and boards
  Reply With Quote
Old 08-01-2014, 06:31 AM   #868 (permalink)
Dreamer
 
Join Date: Nov 2013
Location: Australia
Posts: 350
Thanks: 95
Thanked 214 Times in 151 Posts
Quote:
Originally Posted by MPaulHolmes View Post
But RX still goes to the max232?
I am picturing something like this. Would that be close flores?
  Reply With Quote
Old 08-04-2014, 03:13 AM   #869 (permalink)
EV Connoisseur
 
Join Date: Aug 2010
Location: Amsterdam
Posts: 309
Thanks: 70
Thanked 109 Times in 90 Posts
Yes.. plus the voltage divider on the tx.. like so:

  Reply With Quote
Old 08-06-2014, 10:33 AM   #870 (permalink)
Dreamer
 
Join Date: Nov 2013
Location: Australia
Posts: 350
Thanks: 95
Thanked 214 Times in 151 Posts
I just collected my AC motor for the ev. It's a 132m frame 75kw rewound industrial motor which comes fitted with an encoder bearing. The encoder is 64 ppr. Will this be enough or will i need to add an external encoder with more pulses per revolution?
The encoder bearing is the same one as this eBay listing.
NEW SKF Sensor Bearing BMB 6206 064S2 UA002A Electric Motor Bearing | eBay

  Reply With Quote
The Following User Says Thank You to Astro For This Useful Post:
MPaulHolmes (08-06-2014)
Reply  Post New Thread


Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Paul & Sabrina's cheap DIY 144v motor controller MPaulHolmes Open ReVolt: open source DC motor controller 7381 08-02-2023 10:55 PM
Paul & Sabrina's Cheap EV Conversion MPaulHolmes Fossil Fuel Free 542 11-12-2016 09:09 PM
Contest! Name Paul & Sabrina's controller MetroMPG Forum News & Feedback 120 10-22-2011 01:59 PM



Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com