Hi Dialog Team,
I've been experiencing an odd behavior with the boot loader over temperature. We are currently using the Murata ZY module with your DA14580 integrated onboard. We are currently using the UART boot loader (Pins 4 and 5) to program it from an external micro controller at startup. At room temperature (25C), the Murata module will continuously send repeated requests to the external micro until it responds with the correct sequence. When we try to do a cold start with this module below -10C, the boot loader will send one or two requests then stop. In the app note AN-B-001 (Page 5), the diagram shows that the UART sends one request (per line) and will never repeat.
My question is, what should I expect from the boot loader? How many requests should I expect from the boot loader on the UART line? Also, why does the boot loader act differently below -10C?
Thanks in Advance,
Jim
Hi jbowles,
Give us some time to check.
Thanks MT_dialog
Are there any updates on this issue?
Thanks,
Jim
Hi jbowles,
Sorry for the delayed answer. The proper operation of the bootloader is the one described in the documentation, the most probable reason for what you are experiencing is probably because of the power supply. Different behaviour has been noticed in different power supply voltages. The bootloader measures the power supply after the end of each loop of the booting sequence and if the voltage of the power supply is above a threashold then the da runs the booting sequence again.
Thanks MT_dialog
Just to clarify, if the supply voltage is below a certain threshold where the booting sequence is not triggered, will that have any ill affect to the operation of the part if it is able to boot from an external micro?
We've tried varying the supply voltage to the module (tried 2.7, 3.0 and 3.3V) and the module would still only send one or two requests before stopping.
Thanks,
Jim
Hi Dialog Team,
Any updates on my last question?
Thanks,
Jim
Hi jbowles,
Sorry for the delay, i didn't had any response yet, i pinged the team, i will let you know as soon as i get a something..
Thanks MT_dialog
Hi jbowles,
Sorry for the delayed answer, i just got a response from the hardware team. The bootrom in the da is using the ADC as i ve told you to measure the voltage level. For some reason the first measurement of the ADC is sometimes incorrect and results in a single execution of the serial boot sequence. Other devices will show a continious execution of the serial sequence. The behaviour is temperature dependent. The application should be ready to catch the first boot sequence as soon as a power on reset or external reset has been provided.
Thanks MT_dialog