| |
see the v1.21 parts list in the hardware section, for the following info:
re: R4's value. Depending on the variety of the manufacture of the
HC132 chip, R4 should be
either 3.83K (Digikey 3.83KXBK-ND) or 6.81K (Digikey 6.81KXBK-ND). To
test this, type
"bit_set(0x1000, 0x40);" from the IC command line, and when the IR
output circuit is active (as
evidenced by the IR OUT LED9 being on), measure the frequency at pin 3
of the HC132. It should be
38 to 40 kHz. Use the 6.81K resistor to lower the frequency if it's too
high; use the 3.83K
resistor to raise it if it's too low.
Fred
On Sunday, November 11, 2001, at 07:59 AM, Chris Benndorf wrote:
> Hi $ALL!
>
> I just assembled a handyboard. The assembly documentation (hba.pdf)
> says, that there should be a ~40kHz square wave at pin 2 of U9
> (HC04). My frequency counter shows 72 kHz... So I took a new
> capacitor (682) and a new resistor (3k83) but that makes no
> difference. Any hints how that comes?
>
> THX
> Chris
> --
> Chris Benndorf
> chrisb@ganzfix.de
> http://www.ganzfix.de
> Phone: +49 6356 989333
>
|
|
Message has 1 Reply:
 | | Re: IR port
|
| Am Sonntag 11 November 2001 22:04 schrieb Fred G. Martin: (...) Aaahhh, 6.81K gives me 43kHz - I think I will have a look at some higher values. I did not know that the HC132 could be that much of a difference! Big THX! Chris (23 years ago, 11-Nov-01, to lugnet.robotics.handyboard)
|
Message is in Reply To:
| | IR port
|
| Hi $ALL! I just assembled a handyboard. The assembly documentation (hba.pdf) says, that there should be a ~40kHz square wave at pin 2 of U9 (HC04). My frequency counter shows 72 kHz... So I took a new capacitor (682) and a new resistor (3k83) but (...) (23 years ago, 11-Nov-01, to lugnet.robotics.handyboard)
|
3 Messages in This Thread:
 
- Entire Thread on One Page:
- Nested:
All | Brief | Compact | Dots
Linear:
All | Brief | Compact
This Message and its Replies on One Page:
- Nested:
All | Brief | Compact | Dots
Linear:
All | Brief | Compact
|
|
|
|
