Morning,
Has anybody got any experience with these ?
https://www.mas-oy.com/2016/06/01/time- ... er-module/
I am experiencing a problem, i believe its noise bit but 100% sure.
I am using the flowcharts from here which martin very kindly changed for me, V9 versions attached
https://www.matrixtsl.com/mmforums/view ... 623#p27623
I with the clock module on a breadboard and a scope on the output i can see the output.
connect the module on a EB breadboard and LCD Display - no output from the module checked with scope.
Tried to cycle the control pin to reset the module - still no output
I believe its noise related as i also found i get no output from the clock module if it is too close to my monitor.
Have powered the clock module from a separate supply and moved the EB breadboard with a ribbon cable extension (Matrix 100mm one) as far away as i can - nothing
I Have also tried fitting 10nf ceramic capacitor to supplies.
Any suggestions
Steve
DCF77 Clock Module
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steve001
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DCF77 Clock Module
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steve001
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Re: DCF77 Clock Module
Evening All,
I Received a reply from the manufacturer with some guidance, made some interesting reading.
I will have a go and post my findings.
The ferrite bar antenna should be located as far as possible from conductive metal walls, PCB ground planes or ferromagnetic
objects (speakers). All those objects affect the antenna tuning and can attenuate the received signal. To avoid noise coupling
the ferrite antenna should also not be pointing towards noisy electronic circuits. It is a good practice to turn off all
unnecessary electronic circuits when receiving the weak radio transmission.
Getting a signal
The antenna is sensitive for magnetic and electric disturbances. As an example, in digital radio controlled clocks
it is known that LCD displays, refreshed using a 32Hz signal, has a 1875th odd harmonic hitting exactly at 60kHz
and its amplitude can be strong enough (μVrms level) to reduce the sensitivity. The antenna and module
placement is critical and one should maximize distance to other disturbing electronics and metal/ferrous parts
which might affect the antenna and the reception.
A good place to start is to put the module close to a window and turn the antenna to an optimal position relative
the transmitter. As the second step trigger the fast startup by moving PDN control from
power down (PDN=VDD) to power up (PDN=VSS) which will make the AGC find its level within a few seconds if
the receiving conditions are sufficient. Initially the OUT signal should be high but soon after finding a signal (or
disturbance in case of poor SNR) the output goes low and after a few seconds it should start receiving pulses. If
the output stays low all the time there is probably some disturbance stronger than the signal. If the signal is bad,
change location and repeat the fast startup by setting PDN=VDD (power down) to PDN=VSS (power up).
Please note that if PDN control is not used but the P1 pin (PDN) is permanently tied to GND (receiver on), the
start-up time before the receiver finds the signal can take a few minutes.
Steve
I Received a reply from the manufacturer with some guidance, made some interesting reading.
I will have a go and post my findings.
The ferrite bar antenna should be located as far as possible from conductive metal walls, PCB ground planes or ferromagnetic
objects (speakers). All those objects affect the antenna tuning and can attenuate the received signal. To avoid noise coupling
the ferrite antenna should also not be pointing towards noisy electronic circuits. It is a good practice to turn off all
unnecessary electronic circuits when receiving the weak radio transmission.
Getting a signal
The antenna is sensitive for magnetic and electric disturbances. As an example, in digital radio controlled clocks
it is known that LCD displays, refreshed using a 32Hz signal, has a 1875th odd harmonic hitting exactly at 60kHz
and its amplitude can be strong enough (μVrms level) to reduce the sensitivity. The antenna and module
placement is critical and one should maximize distance to other disturbing electronics and metal/ferrous parts
which might affect the antenna and the reception.
A good place to start is to put the module close to a window and turn the antenna to an optimal position relative
the transmitter. As the second step trigger the fast startup by moving PDN control from
power down (PDN=VDD) to power up (PDN=VSS) which will make the AGC find its level within a few seconds if
the receiving conditions are sufficient. Initially the OUT signal should be high but soon after finding a signal (or
disturbance in case of poor SNR) the output goes low and after a few seconds it should start receiving pulses. If
the output stays low all the time there is probably some disturbance stronger than the signal. If the signal is bad,
change location and repeat the fast startup by setting PDN=VDD (power down) to PDN=VSS (power up).
Please note that if PDN control is not used but the P1 pin (PDN) is permanently tied to GND (receiver on), the
start-up time before the receiver finds the signal can take a few minutes.
Steve