* See http://www.robot-electronics.co.uk/files/eth008b.pdf for device
* capabilities and a protocol discussion.
* See https://github.com/devantech/devantech_eth_python for Python
- * source code which is maintained by the vendor.
+ * source code which is maintained by the vendor. The untested parts
+ * of this sigrok driver are based on version 0.1.2 of this Python
+ * code which is MIT licensed (corresponds to commit 0c0080b88e29),
+ * and example code in ZIP archives provided on the shop's products'
+ * pages.
*
* The device provides several means of communication: HTTP requests
* (as well as an interactive web form). Raw TCP communication with
* TODO
* - Add support for other models. Currently exclusively supports the
* ETH008-B model which was used during implementation of the driver.
+ * (Descriptions for more models were added, their operation is yet
+ * to get verified.) Getting relay state involves variable length
+ * responses, bits appear to be in little endian presentation.
+ * - Add support for absent relay output channels (ETH484 lacks R5..R8).
+ * - Add support for digital inputs. ETH484 has command 0x25 which gets
+ * two bytes, the second byte carries eight digital input bits.
+ * ETH1610 has 16 inputs, evaluates both bytes. Is data format u16be?
+ * ETH8020 support code is inconsistent, implements two accessors
+ * which either retrieve two or three bytes, while callers access the
+ * fourth byte of these responses? Cannot have worked, seems untested.
+ * - Add support for analog inputs. ETH484 has command 0x32 which takes
+ * a channel number, and gets two bytes which carry a u16be value(?).
+ * So does ETH8020. Channel count differs across models.
+ * - Are there other models of interest? ETH1610 product page reads
+ * as if the card had 10 relays (strict output), and 16 inputs which
+ * could either be used in analog mode, or simply get interpreted as
+ * digital input?
* - Add support for password protection?
* - See command 0x79 to "login" (beware of the differing return value
* compared to other commands), command 0x7a to check if passwords
CMD_DIGITAL_INACTIVE = 0x21,
CMD_DIGITAL_SET_OUTPUTS = 0x23,
CMD_DIGITAL_GET_OUTPUTS = 0x24,
+ CMD_DIGITAL_GET_INPUTS = 0x25,
+ CMD_ANALOG_GET_INPUT = 0x32,
CMD_ASCII_TEXT_COMMAND = 0x3a,
CMD_GET_SERIAL_NUMBER = 0x77,
CMD_GET_SUPPLY_VOLTS = 0x78,
if (!devc)
return SR_ERR_ARG;
+ /* Unconditionally get the state of digital output. */
rx_size = devc->model->width_do;
if (rx_size > sizeof(rsp))
return SR_ERR_NA;
have &= devc->mask_do;
devc->curr_do = have;
+ /*
+ * Get the state of digital inputs when the model supports them.
+ * Firmware of other models happens to not respond to unknown
+ * requests. Responses seem to have identical size across all
+ * models. Payload is assumed to be u16 be formatted. Must be
+ * verified when other models are seen.
+ *
+ * Caching the state of analog inputs is condidered undesirable.
+ */
+ if (devc->model->ch_count_di) {
+ rx_size = sizeof(uint16_t);
+ if (rx_size > sizeof(rsp))
+ return SR_ERR_NA;
+
+ wrptr = req;
+ write_u8_inc(&wrptr, CMD_DIGITAL_GET_INPUTS);
+ ret = send_then_recv(serial, req, wrptr - req, rsp, rx_size);
+ if (ret != SR_OK)
+ return ret;
+ rdptr = rsp;
+
+ switch (rx_size) {
+ case 2:
+ have = read_u16be_inc(&rdptr);
+ break;
+ default:
+ return SR_ERR_NA;
+ }
+ have &= (1UL << devc->model->ch_count_di) - 1;
+ devc->curr_di = have;
+ }
+
return SR_OK;
}
return SR_OK;
}
+SR_PRIV int devantech_eth008_query_di(const struct sr_dev_inst *sdi,
+ const struct sr_channel_group *cg, gboolean *on)
+{
+ struct dev_context *devc;
+ struct channel_group_context *cgc;
+ uint32_t have;
+ int ret;
+
+ /* Unconditionally update the internal cache. */
+ ret = devantech_eth008_cache_state(sdi);
+ if (ret != SR_OK)
+ return ret;
+
+ /*
+ * Only reject unexpected requeusts after the update. Get the
+ * individual channel's state from the cache of all channels.
+ */
+ devc = sdi->priv;
+ if (!devc)
+ return SR_ERR_ARG;
+ if (!cg)
+ return SR_ERR_ARG;
+ cgc = cg->priv;
+ if (!cgc)
+ return SR_ERR_BUG;
+ if (cgc->index >= devc->model->ch_count_di)
+ return SR_ERR_ARG;
+ have = devc->curr_di;
+ have >>= cgc->index;
+ have &= 1 << 0;
+ if (on)
+ *on = have ? TRUE : FALSE;
+
+ return SR_OK;
+}
+
+SR_PRIV int devantech_eth008_query_ai(const struct sr_dev_inst *sdi,
+ const struct sr_channel_group *cg, uint16_t *adc_value)
+{
+ struct sr_serial_dev_inst *serial;
+ struct dev_context *devc;
+ struct channel_group_context *cgc;
+ uint8_t req[2], *wrptr;
+ uint8_t rsp[2];
+ const uint8_t *rdptr;
+ uint32_t have;
+ int ret;
+
+ serial = sdi->conn;
+ if (!serial)
+ return SR_ERR_ARG;
+ devc = sdi->priv;
+ if (!devc)
+ return SR_ERR_ARG;
+ if (!cg)
+ return SR_ERR_ARG;
+ cgc = cg->priv;
+ if (!cgc)
+ return SR_ERR_ARG;
+ if (cgc->index >= devc->model->ch_count_ai)
+ return SR_ERR_ARG;
+
+ wrptr = req;
+ write_u8_inc(&wrptr, CMD_ANALOG_GET_INPUT);
+ write_u8_inc(&wrptr, cgc->number & 0xff);
+ ret = send_then_recv(serial, req, wrptr - req, rsp, sizeof(rsp));
+ if (ret != SR_OK)
+ return ret;
+ rdptr = rsp;
+
+ /*
+ * TODO The u16 BE format is a guess. Needs verification.
+ * As is the unit-less nature of that value.
+ */
+ have = read_u16be_inc(&rdptr);
+ if (adc_value)
+ *adc_value = have;
+
+ return SR_OK;
+}
+
SR_PRIV int devantech_eth008_query_supply(const struct sr_dev_inst *sdi,
const struct sr_channel_group *cg, uint16_t *millivolts)
{
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