RF_TXCTRL - Mistake in Official User Manual Version 2.18 or Mistake in Official Github Repository

FIRSTDRAGON · September 1, 2020, 1:58am

Hello Decawave,

Can you please comment on the following issue:

The latest DW1000 user manual version 2.18 shows the RF_TXCTRL configuration value 0x001E3FE3 for channel 5. this sets the two least significant bits which are actually supposed to have no function.

However, your official GitHub repository shows the following RF_TXCTRL configuration value 0X001E3FE0 for channel 5.

github.com

Decawave/uwb-dw1000/blob/master/hw/drivers/uwb/uwb_dw1000/include/dw1000/dw1000_regs.h

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

/**

This file has been truncated. show original

My simple question is: Which value is the correct value ?

Best regards

seppe · September 2, 2020, 2:20pm

Hi

See the description of the “Reserved” fields in RF_TXCTRL, in the latest version of the DW1000 user manual (v2.18) it states “Program only as directed in Table 38”.

Note that the “official GitHub repository” you mentioned is not really the latest “officially” supported driver. This can be found on our website: https://www.decawave.com/wp-content/uploads/2019/01/dw1000_api_rev2p14.zip.
This uses the 0x001E3FE3UL value defined in the user manual.

seppe · September 2, 2020, 3:15pm

Just did a bit of research, 0x001E3FE3 is definitely the correct value to use.

Using the old value can result in ~2dB spurs in the channel 5 TX spectrum, which can cause issues with regulation / limit the TX power that can be used to meet regulation.

Again, the Github repository does not contain the latest official version of the DW1000 decadriver. I created an issue on the repository so the team responsible is aware.

Dan · September 3, 2020, 1:05am

There are some other discrepancies with UG and API.
Has anyone already received an answer from DW team on the issues found?
Look like nobody tracking issues reported by users.