Satoru Yoshida
measure ohm of HS15P
Fork of
Frequency_counter
by 
Neel Shah
This test program measures ohm of HS15P, humidity sensor.
| C(micro F) with LMC555 | 0.1 | 0.15 | 0.22 | 0.33 | 0.47 | 0.68 | 1 |
| CONV_KILO_OHM | 0.0072 | 0.0048 | 0.0033 | 0.0022 | 0.0015 | 0.0011 | 0.00072 |
If you get 2500 microseconds as interrupt time interval , it means 18 kilo ohm when 0.1 micro F. ( = 2500 * 0.0072 )
- ohm of HS15P is calculated from pulse interval of LMC555.
- CONV_KILO_OHM will be used.
- this program reads interval time.between interrupt in the P8.
- takes ON the P9 to oscillate LMC555 as short as enough to measure interval time
- last several interval times will be used for calculation.
- the time is defined as READ_TIMER .
- In current circit, VDD of LMC555 is about 1.55V, AC 0.4V between pins of HS15P.
- LMC555 consumes 120 micro A while oscillation, 90 micro A when level of P9 is OFF. (reset is ON)
- Total 1-2mA is consumed in the circit.
Related nootbook : https://mbed.org/users/strysd/notebook/measure_humidity_with_hs15p_and_lmc555/
History
sync libraries
2014-05-11, by strysd [Sun, 11 May 2014 05:08:29 +0000] rev 8
sync libraries
sync libraries
2013-11-06, by strysd [Wed, 06 Nov 2013 07:38:20 +0000] rev 7
sync libraries
separate defines
2013-08-11, by strysd [Sun, 11 Aug 2013 08:34:00 +0000] rev 6
separate defines
change interrupt mode and wait time
2013-06-04, by strysd [Tue, 04 Jun 2013 06:14:19 +0000] rev 5
change interrupt mode and wait time
define constants
2013-06-03, by strysd [Mon, 03 Jun 2013 15:04:08 +0000] rev 4
define constants
define range of not ready
2013-06-03, by strysd [Mon, 03 Jun 2013 12:36:37 +0000] rev 3
define range of not ready
remove unneeded pulldown
2013-06-01, by strysd [Sat, 01 Jun 2013 07:49:57 +0000] rev 2
remove unneeded pulldown
first commit
2013-06-01, by strysd [Sat, 01 Jun 2013 05:44:10 +0000] rev 1
first commit
Can read pulses on the pin and convert them into frequency count
2013-02-03, by Neel [Sun, 03 Feb 2013 21:06:02 +0000] rev 0
Can read pulses on the pin and convert them into frequency count