nRF24L01+

RE: nRF24L01+

ketiljo — Fri, 03 Aug 2018 11:54:50 GMT

There's no reason for just ACK to be lost like this. Connect the antenna properly first and then check how it works.

ESD protection diodes for RF must have very low capacitance, < 0.5 pF. Protection on the antenna pin is rarely needed though.

RE: nRF24L01+

JasonWu — Tue, 31 Jul 2018 14:35:29 GMT

Does this special protection diodes have a recommended model? and which position does the diode add to our board?

I'm very sorry that my expression may not be very clear when I describe the problem.by the way, the function of my device is to transmit a message from one device to another(like a bridge). For example, the signal comes from a temperature sensor is received by our device , and then sends to another device. That means our device firstly is in RX state and then changes to Tx state when received message. The secitivity of Rx AND Tx is OK, but only sometimes lost ACK when Tx status at A rate about 40%.

devzone.nordicsemi.com/.../antenna.docx

RE: nRF24L01+

ketiljo — Tue, 31 Jul 2018 13:34:22 GMT

That must be solved by using special protection diodes if necessary. Disconnecting ground isn't the way to protect a radio against ESD

RE: nRF24L01+

JasonWu — Tue, 31 Jul 2018 13:27:18 GMT

Do you have any good ways to solve this problem?

RE: nRF24L01+

JasonWu — Tue, 31 Jul 2018 13:26:01 GMT

Thank you for your answer. We will connect the coaxial cable to the module according to your method. Then test the receiver performance.

However, according to your method, there will be some electromagnetic compatibility problems, such as electrostatic discharge immunity test. Static electricity will enter the PCB board through coaxial cable, causing damage to the equipment.

RE: nRF24L01+

ketiljo — Tue, 31 Jul 2018 13:00:04 GMT

Try connecting the shield of the coax cable to the module, the antenna won't work well without this. So it's possible that it's the antenna that causes the ACK to be lost. You might be better off using the U.FL connector that was (?) on the module with a corresponding connector on the antenna coax.

Note that if you get the module from another place than our distributors, it's a chance that the nRF24L01+ chip may be counterfeit and may have reduced RF performance.

RE: nRF24L01+

JasonWu — Tue, 31 Jul 2018 10:37:58 GMT

I'm terribly sorry to sort out the data for so long.The attachment section of the mail has the information you need.(the schematic (nRF24L01+ part only), layout of the RF section and antenna and the crystal spec)

devzone.nordicsemi.com/.../Reriver1.0-Sch.pdf devzone.nordicsemi.com/.../Detailed-information.docx

RE: nRF24L01+

ketiljo — Tue, 31 Jul 2018 08:25:28 GMT

There can be many reasons for this. You can noise or disturbance on the channel (WLAN etc), the sensitivity may be low due to antenna or layout issues, the crystal frequency may be wrong.

Can you post the schematic (nRF24L01+ part only), layout of the RF section and antenna and the crystal spec please?