ESB on nRF51822 with >32 byte payload

[Christopher Humphrey]

I'm working on a project where we're having mulitple nRF51822 chips communicate in a multiceiver way. When we bought the nRF51822 chips, the technical sales rep claimed that they could do ESB with up to 256 byte payloads. But looking into the Nordic n51 DK headers (nrf_esb_constants.h specifically), I see:

#define NRF_ESB_CONST_MAX_PAYLOAD_LENGTH 32 ///< Maximum allowed payload length in bytes.

In practice, this 32-byte limit seems to be enforced; larger packets do not go through.

Is there any way to get bigger ESB payloads on this hardware? Should I be using a different library?

[Daniel Veilleux]

Hello Christopher,

The 32-byte limitation in the official esb_arm.lib implementation is enforced in order to make the library backwards-compatible with older Nordic devices.

If you are only using nRF51 devices then you can use larger payloads with the unofficial ESB library that is maintained by the support team: "github.com/.../nrf51-micro-esb". See the UESB_CORE_MAX_PAYLOAD_LENGTH constant in micro_esb.h.