Update some outdated technical docs (#1190)

* update outdated libhackrf documentation

* update outdated hackrf_sweep documentation

docs/source/hackrf_sweep.rst

@@ -14,9 +14,9 @@ Usage
     [-p antenna_enable] # Antenna port power, 1=Enable, 0=Disable
     [-l gain_db] # RX LNA (IF) gain, 0-40dB, 8dB steps
     [-g gain_db] # RX VGA (baseband) gain, 0-62dB, 2dB steps
-    [-n num_samples] # Number of samples per frequency, 8192-4294967296
-    [-w bin_width] # FFT bin width (frequency resolution) in Hz
+    [-w bin_width] # FFT bin width (frequency resolution) in Hz, 2445-5000000
     [-1] # one shot mode
+    [-N num_sweeps] # Number of sweeps to perform
     [-B] # binary output
     [-I] # binary inverse FFT output
     -r filename # output file
@@ -112,8 +112,8 @@ Running ``hackrf_sweep -f 2400:2490`` gives the following example results:
     - -66.02 	
     - -62.12
 
-Two ranges of 5 MHz are analyzed at once from the same set of samples, so a single timestamp applies to the whole range.
+Each sweep across the entire specified frequency range is given a single time stamp.
 
 The fifth column tells you the width in Hz (1 MHz in this case) of each frequency bin, which you can set with ``-w``. The sixth column is the number of samples analyzed to produce that row of data.
 
-Each of the remaining columns shows the power detected in each of several frequency bins. In this case there are five bins, the first from 2400 to 2401 MHz, the second from 2401 to 2402 MHz, and so forth.
+Each of the remaining columns shows the power detected in each of several frequency bins. In this case there are five bins, the first from 2400 to 2401 MHz, the second from 2401 to 2402 MHz, and so forth.

docs/source/libhackrf_api.rst

@@ -197,6 +197,8 @@ Compute nearest freq for bw filter (manual filter)
 Reading and Writing Registers
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
+These low level functions are intended for debugging purposes only.
+
 
 HackRF MAX2837 Read
 ^^^^^^^^^^^^^^^^^^^
@@ -282,7 +284,7 @@ Updating Firmware
 HackRF CPLD Write
 ^^^^^^^^^^^^^^^^^
 
-Device will need to be reset after hackrf_cpld_write.
+A bitstream is written to the CPLD by the firmware during normal operation (since release 2021.03.1). This function writes a bitstream to the CPLD's flash which is not necessary for normal use. The device will need to be reset by physically pressing the reset button after hackrf_cpld_write.
 
 **Syntax:** ``int hackrf_cpld_write(hackrf_device* device, unsigned char* const data, const unsigned int total_length)``
 
@@ -462,35 +464,37 @@ These values identify the board type of the connected hardware. This value can b
 
   * - Board 	
     - Frequency range 	
-    - Bandwidth 	
+    - Sample Rate
     - Antenna port power
   * - HackRF One 	
-    - 1MHz - 6Ghz 	
-    - 20MHz 	
+    - 1 MHz–6 GHz
+    - 20 Msps
     - Yes
   * - Jawbreaker 	
-    - 10MHz - 6GHz 	
-    - 20MHz 	
+    - 10 MHz–6 GHz
+    - 20 Msps
+    - No
+  * - rad1o 	
+    - 50 MHz–4 GHz
+    - 20 Msps
     - No
-  * - Rad1o 	
-    - 50MHz - 4GHz 	
-    - 20MHz 	
-    - Unknown
   * - Jellybean 	
     - N/A 	
-    - 20MHz 	
+    - 20 Msps
     - No
 
-Most boards will identify as HackRF One, Jawbreaker or Rad1o. Jellybean was a pre-production revision of HackRF. No hardware device should intentionally report itself with an invalid board ID.
+Most boards will identify as HackRF One, Jawbreaker, or rad1o. Jellybean was a pre-production revision of HackRF that is no longer supported. No hardware device should intentionally report itself with an unrecognized or undetected board ID.
 
 .. code-block :: sh
 
 	enum hackrf_board_id {
 		BOARD_ID_JELLYBEAN  = 0,
 		BOARD_ID_JAWBREAKER = 1,
-		BOARD_ID_HACKRF_ONE = 2,
+		BOARD_ID_HACKRF1_OG = 2,
 		BOARD_ID_RAD1O = 3,
-		BOARD_ID_INVALID = 0xFF,
+		BOARD_ID_HACKRF1_R9 = 4,
+		BOARD_ID_UNRECOGNIZED = 0xFE,
+		BOARD_ID_UNDETECTED = 0xFF,
 	};
 
 
@@ -512,18 +516,19 @@ USB Product IDs
 Transceiver Mode
 ^^^^^^^^^^^^^^^^
 
-HackRF can operate in three main transceiver modes, Receive, Transmit and Signal Source. There is also a CPLD update mode which is used to write firmware images to the CPLD.
+HackRF can operate in four main transceiver modes: Receive, Transmit, Signal Source, and Sweep. There is also a CPLD update mode which is used to write firmware images to the CPLD flash.
 
 The transceiver mode can be changed with ``hackrf_set_transceiver_mode`` with the value parameter set to one of the following:
 
 .. code-block:: sh
 
 	enum transceiver_mode_t {
-		TRANSCEIVER_MODE_OFF = 0,
-		TRANSCEIVER_MODE_RX = 1,
-		TRANSCEIVER_MODE_TX = 2,
-		TRANSCEIVER_MODE_SS = 3,
-		TRANSCEIVER_MODE_CPLD_UPDATE = 4
+		HACKRF_TRANSCEIVER_MODE_OFF = 0,
+		HACKRF_TRANSCEIVER_MODE_RECEIVE = 1,
+		HACKRF_TRANSCEIVER_MODE_TRANSMIT = 2,
+		HACKRF_TRANSCEIVER_MODE_SS = 3,
+		TRANSCEIVER_MODE_CPLD_UPDATE = 4,
+		TRANSCEIVER_MODE_RX_SWEEP = 5,
 	};
 
 Receive mode (TRANSCEIVER_MODE_RX) is used to stream samples from the radio to the host system. Use ``hackrf_set_freq`` to set the center frequency of receiver and ``hackrf_set_sample_rate`` to set the sample rate (effective bandwidth).
@@ -551,6 +556,8 @@ Function return values
 		HACKRF_ERROR_STREAMING_THREAD_ERR = -1002,
 		HACKRF_ERROR_STREAMING_STOPPED = -1003,
 		HACKRF_ERROR_STREAMING_EXIT_CALLED = -1004,
+		HACKRF_ERROR_USB_API_VERSION = -1005,
+		HACKRF_ERROR_NOT_LAST_DEVICE = -2000,
 		HACKRF_ERROR_OTHER = -9999,
 	};