The only way to flash the image in TL-WR802N v4 is to use tftp recovery mode in U-Boot:
openwrt-ramips-mt76x8-tplink_tl-wr802n-v4-squashfs-tftp-recovery.bin to tp_recovery.bin and place it in the TFTP server folder.This device uses 1.3 watts at idle with OpenWRT and 4 SSIDs configured. Measured with high accuracy ELV Energy master.
Even WR802Nv4 is sold, there are hardware differences. Devices beginning with serialnumer 219 and 220 support 25 dBm maximum transmit power, whereas devices with serial number beginning with 221 support only 22 dBm maximum transmit power. In all cases Wifi chipset is MediaTek MT76x8 802.11bgn. Or maybe this is dependant on TP-Link department. So italy would be 25 dBm wheras Germany would be 22 dBm, details see here https://forum.openwrt.org/t/wr802n-different-maximum-transmit-power-depending-on-batch/116958/6
Up to 4 SSIDs are supported on all those versions.
IEEE 802.1Q VLANs are supported.
Output of iw phy for all for Italy / 25 dBm version with country code AU.
Wiphy phy0 wiphy index: 0 max # scan SSIDs: 4 max scan IEs length: 2257 bytes max # sched scan SSIDs: 0 max # match sets: 0 Retry short limit: 7 Retry long limit: 4 Coverage class: 0 (up to 0m) Device supports AP-side u-APSD. Device supports T-DLS. Available Antennas: TX 0x3 RX 0x3 Configured Antennas: TX 0x3 RX 0x3 Supported interface modes: * IBSS * managed * AP * AP/VLAN * monitor * mesh point * P2P-client * P2P-GO Band 1: Capabilities: 0x1fe HT20/HT40 SM Power Save disabled RX Greenfield RX HT20 SGI RX HT40 SGI TX STBC RX STBC 1-stream Max AMSDU length: 3839 bytes No DSSS/CCK HT40 Maximum RX AMPDU length 65535 bytes (exponent: 0x003) Minimum RX AMPDU time spacing: No restriction (0x00) HT TX/RX MCS rate indexes supported: 0-15 Frequencies: * 2412 MHz [1] (25.0 dBm) * 2417 MHz [2] (25.0 dBm) * 2422 MHz [3] (25.0 dBm) * 2427 MHz [4] (25.0 dBm) * 2432 MHz [5] (25.0 dBm) * 2437 MHz [6] (25.0 dBm) * 2442 MHz [7] (25.0 dBm) * 2447 MHz [8] (25.0 dBm) * 2452 MHz [9] (25.0 dBm) * 2457 MHz [10] (25.0 dBm) * 2462 MHz [11] (25.0 dBm) * 2467 MHz [12] (25.0 dBm) * 2472 MHz [13] (25.0 dBm) * 2484 MHz [14] (disabled) valid interface combinations: * #{ IBSS } <= 1, #{ managed, AP, mesh point, P2P-client, P2P-GO } <= 4, total <= 4, #channels <= 1, STA/AP BI must match HT Capability overrides: * MCS: ff ff ff ff ff ff ff ff ff ff * maximum A-MSDU length * supported channel width * short GI for 40 MHz * max A-MPDU length exponent * min MPDU start spacing max # scan plans: 1 max scan plan interval: -1 max scan plan iterations: 0 Supported extended features: * [ RRM ]: RRM * [ CQM_RSSI_LIST ]: multiple CQM_RSSI_THOLD records * [ CONTROL_PORT_OVER_NL80211 ]: control port over nl80211 * [ TXQS ]: FQ-CoDel-enabled intermediate TXQs * [ AIRTIME_FAIRNESS ]: airtime fairness scheduling * [ AQL ]: Airtime Queue Limits (AQL) * [ SCAN_RANDOM_SN ]: use random sequence numbers in scans * [ SCAN_MIN_PREQ_CONTENT ]: use probe request with only rate IEs in scans * [ CONTROL_PORT_NO_PREAUTH ]: disable pre-auth over nl80211 control port support * [ DEL_IBSS_STA ]: deletion of IBSS station support * [ SCAN_FREQ_KHZ ]: scan on kHz frequency support * [ CONTROL_PORT_OVER_NL80211_TX_STATUS ]: tx status for nl80211 control port support</nowiki>