[EHS6] Specifications GPIO | Telit Cinterion IoT Developer Community
March 3, 2016 - 8:43am, 3671 views
I was wondering where to find the exact specs for the EHS6s GPIO's. For instants I cannot find what the minimum pulse time ***** to be to detect a change on a GPIO input.
For a project I want to use the EHS6T-USB terminals GPIOs inputs connected to a S0 port on a electricity meter with a minimum pulse length of 20ms. I was wondering if that is possible. I need 8 GPIOs so the COUNTER is not a option.
In the HW specification I cannot find information like this.
I found out dat a pulse of ~20ms will be missed half of the time.
I was wrong. Pulses with a width of ~20ms and around 1Hz did work correcty.
I know that this is probably quite stupid question, but how did you detect changes? Manualy or with listener? You probably used listener right? I was doing something similar, where I used function generator to generate pulses, but I can't remember how long pulses where. I only remember that problems acured if frequency was bigger then 3Hz.
I need a *** of 25Hz. Looks like it is not gona work :)
You can search for the information about GPIO in HW descriptions for module and terminal and AT commands specification also.
But you're right that there are no frequencies. Generally only pulse counter should be used for ******** pulses and it is written in the AT commands specification that it can measure from 0 to 1000 pulses per second. The measurement starts within <50ms after the OK result. If the pulse counter is controlled from Java this delay may, in rare cases and depending on the system load, be longer.
Other GPIO's should rather be used for detecting some state changes. For pulse counter the pulses are counted somewhere in the low level. You can't have any guarantee that if you implement your own pulse counter on top of AT interface on in Java you'll be able to catch all pulses especially with high frequency. These high level API's have lower priorities in the system then many other processes.
Problem is that I need 8 of them and there is only one counter available.
You can always do some testing. But you may need to employ some external hardware.