Root/TODO

Source at commit 5392401c0acbabadccf1e47abe59f05e25db9a7f created 8 years 4 months ago.
By Werner Almesberger, tools/atrf-rssi/: added menu for regulation area selection
1Current stuff
2-------------
3
4- add spi_atben driver, for improved performance and to serve as an
5  example for spi_atusb
6
7- need to document fab workflow in makefiles/Makefile.kicad
8
9  Deadline: before FISL 12 :-)
10
11- boot.hex is now bigger than 4 kB. Need to split USB stack build into
12  "lean" and "fat" version.
13
14  Work-around: those wishing to build their boot loader should use
15  commit ce16a16.
16
17- atusb/fw/ design flaw: we can send an interrupt queued in EP1 after
18  a control transfer has happened that turns off the interrupt source
19
20  Work-around: none
21
22- atusb/fw/ should combine interrupts so that we don't have to read
23  IRQ_STATUS (this goal may conflict with the synchronization
24  requirement above, though)
25
26- show WLAN channels in atrf-rssi -g
27
28- atusb/fw/: think of a better way to re-enable INT0 after ATUSB_GPIO
29
30- atusb/fw/: remove obsolete atusb requests
31
32
33*** EVERYTHING BELOW NEEDS UPDATING ***
34
35General
36=======
37
38Things not done yet
39-------------------
40
41- document directory hierarchy
42
43- make sure all files have a copyright header or are listed in AUTHORS
44
45- connect all the bits and pieces of the build system
46
47- combine io-parts.h generation
48
49- combine "standard" EP0 commands, such as *_ID and *_BUILD
50
51- implement return to DFU in application's EP0 protocol
52
53- consider removing *_ID and using bcdDevice instead
54
55
56Bugs to fix
57-----------
58
59- builds fail if .version isn't there yet
60
61
62
63atrf
64====
65
66AT86RF230-based IEEE 802.15.4 transceiver. Two variants: one to make a USB
67dongle for use with any Linux host, and one that connects with SPI directly
68inside a Ben.
69
70Update: following Rikard Lindstrom's revelation that we can use the uSD slot
71also just as general GPIOs, the variant that goes inside the Ben can wait a
72bit and the atben board for insertion into the uSD slot is being worked on
73first. We can verify most of the design of a fully integrated board with the
74atben board and the latter will be of greater immediate use.
75
76
77Things done
78-----------
79
80- verify that the Ben can output an a) 16 MHz clock, and b) with +/- 40 ppm
81
82  Done, see ecn/ecn0005.txt. Works fine.
83
84- replace discrete balun and filter with integrated solution, to reduce BOM
85  size, maybe cost, insertion loss, and PCB space (see ATRF/ECN0003)
86
87  Done for atben. At a first glamce, does not seem to affect performance.
88
89- check if we really need three DC blocking caps in the RF path
90
91  Reduced to two in atben without apparent ill effects.
92
93
94Things not done yet
95-------------------
96
97- examine spectrum around carrier frequency and first harmonic to look for
98  obvious distortions. Vary transmit power.
99
100- measure throughput as a function of placement/distance, carrier frequency,
101  and transmit power
102
103- atrf-txrx: suppport "extended mode" with IEEE 802.15.4 CSMA-CA for more
104  realistic throughput figures
105
106- measure full spectrum (ideally up to 25 GHz, but just 2nd and 3rd harmonic
107  will already tell most of the story) with calibrated antenna for FCC/ETSI
108  compliance assessment. Vary transmit power.
109
110- use IEEE 802.15.4 stack from linux-zigbee. The linux-zigbee kernel is
111  currently at 2.6.35. Once 2.6.36 is released, we should have Ben and
112  IEEE 802.15.4 support in the same kernel without further ado.
113
114- change layout of transceiver side of the board for placement inside Ben
115
116- define EMI filters for placement inside Ben
117
118- check USB standard for recommended USB dongle dimensions
119
120- change layout for straight USB dongle
121
122- generate proper BOM
123
124- implement sleep mode
125
126- (atben) verify SPI signal timing, particularly the data clock
127
128
129ccrf
130====
131
132Board similar to the atrf, but with the TI/Chipcon CC2520.
133
134Cancelled. The CC2520 falls under US export restrictions, apparently because
135it contains an AES engine.
136
137
138cntr
139====
140
141Simple USB-based counter to measure a clock's long-time accuracy with
142arbitrarily high precision, by comparing it to an NTP time reference.
143
144
145Things not done yet
146-------------------
147
148- measure duty cycle
149
150- use the LED to display activity on clock input and duty cycle
151
152- consider using a comparator and a DAC to allow for programmable logic levels
153
154- evaluate termination resistance
155
156- document circuit design
157
158- record beats between 16 bit counter polls and use them for the estimate
159  of lost cycles (2*1 is way too optimistic)
160
161- include system clock resolution in accuracy calculation
162
163- consider running shorter sliding windows to estimate drift
164
165- consider detecting unusual half-periods
166
167- consider using a reversed USB connector, to avoid having to cross D+/D- and,
168  worse, VBUS and GND
169
170- test input performance by counting a source that emits a known number of
171  cycles
172
173- consider using historical margins to sanity-check the current margin (if any
174  old.max < curr.min or old.min > curr.max, we have a problem) and to further
175  narrow the effective margin, thus achieving faster convergence. We would have
176  to consider temperature drift of the frequency source in this case.
177
178- find out why frequency measurements always seem to start high and then slowly
179  drop
180

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