{"action":"created","issue":{"url":"https://api.github.com/repos/TMRh20/RF24/issues/137","labels_url":"https://api.github.com/repos/TMRh20/RF24/issues/137/labels{/name}","comments_url":"https://api.github.com/repos/TMRh20/RF24/issues/137/comments","events_url":"https://api.github.com/repos/TMRh20/RF24/issues/137/events","html_url":"https://github.com/TMRh20/RF24/issues/137","id":107353757,"number":137,"title":"nrf24l01+ works fine with RF24 only at 2MBPS","user":{"login":"boguslawb","id":14364078,"avatar_url":"https://avatars.githubusercontent.com/u/14364078?v=3","gravatar_id":"","url":"https://api.github.com/users/boguslawb","html_url":"https://github.com/boguslawb","followers_url":"https://api.github.com/users/boguslawb/followers","following_url":"https://api.github.com/users/boguslawb/following{/other_user}","gists_url":"https://api.github.com/users/boguslawb/gists{/gist_id}","starred_url":"https://api.github.com/users/boguslawb/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/boguslawb/subscriptions","organizations_url":"https://api.github.com/users/boguslawb/orgs","repos_url":"https://api.github.com/users/boguslawb/repos","events_url":"https://api.github.com/users/boguslawb/events{/privacy}","received_events_url":"https://api.github.com/users/boguslawb/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":4,"created_at":"2015-09-19T20:25:50Z","updated_at":"2015-09-21T11:13:58Z","closed_at":null,"body":"Hi\r\nI'm trying to use lower speed then 2MBPS to communicate between two nrf24L01+ modules every 1 second, but only 2MBPS works. The communication require to send 32 bytes between both modules, one is using writeAckPayload() of one struc and then read() method to get  the request (another struct) from the other.\r\nThe other one is using write() then check if available() and read()  payload.\r\n\r\n What should I check ?"},"comment":{"url":"https://api.github.com/repos/TMRh20/RF24/issues/comments/141944385","html_url":"https://github.com/TMRh20/RF24/issues/137#issuecomment-141944385","issue_url":"https://api.github.com/repos/TMRh20/RF24/issues/137","id":141944385,"user":{"login":"TMRh20","id":2610460,"avatar_url":"https://avatars.githubusercontent.com/u/2610460?v=3","gravatar_id":"","url":"https://api.github.com/users/TMRh20","html_url":"https://github.com/TMRh20","followers_url":"https://api.github.com/users/TMRh20/followers","following_url":"https://api.github.com/users/TMRh20/following{/other_user}","gists_url":"https://api.github.com/users/TMRh20/gists{/gist_id}","starred_url":"https://api.github.com/users/TMRh20/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/TMRh20/subscriptions","organizations_url":"https://api.github.com/users/TMRh20/orgs","repos_url":"https://api.github.com/users/TMRh20/repos","events_url":"https://api.github.com/users/TMRh20/events{/privacy}","received_events_url":"https://api.github.com/users/TMRh20/received_events","type":"User","site_admin":false},"created_at":"2015-09-21T11:13:58Z","updated_at":"2015-09-21T11:13:58Z","body":"@boguslawb Try adding the following line to the GettingStarted_CallResponse.ino example sketch after radio.begin():\r\n``` radio.setDataRate(RF24_250KBPS); ```\r\n\r\nThat is an example of how to properly use ACK payloads. If you still have problems @ < 2MBPS then you have some kind of other problem. (not software)\r\n\r\n@rlogiacco \r\n\r\nYou seem to have a pretty good understanding of the retries and ack-payloads, but may be misinterpreting the datasheet or functionality a bit. In my experience, ack payloads are very reliable at any data rate.\r\n\r\n> You should check the datasheet because it states the max ack payload length will get shorter when you reduce the data rate.\r\n\r\nThis is kind of correct and incorrect at the same time, as the max ack payload length is always 32 bytes if the retry periods are adjusted accordingly. You need to allow a minimum of 500uS ARD when setting your retry periods ( ``` radio.setRetries(2,1); ``` will work at any data rate and is guaranteed to work with functional hardware and proper coding ) \r\n\r\n> If you want to use slower data rate you must move away from ack packet payloads.\r\n\r\nAck payloads work fine at any data rate. Technically, slower data rates are actually more reliable and provide better range.\r\n\r\n\r\n\r\n"}}